Ruth Bates, MD

Inspired by the ABIM Foundation’s Choosing Wisely^® campaign, the “Things We Do for No Reason^™” (TWDFNR) series reviews practices that have become common parts of hospital care but may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent clear-cut conclusions or clinical practice standards but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion.

A 62-year-old woman with chronic obstructive pulmonary disease (COPD) presents to the emergency department with shortness of breath, wheezing, and altered mental status (AMS). She is diagnosed with an acute COPD exacerbation with hypercarbic respiratory failure and is treated with nebulized albuterol/ipratropium and intravenous methylprednisolone. The hospitalist orders basic admission laboratory tests, including a thyroid-stimulating hormone (TSH) test for completeness, although she suspects that the patient’s AMS is secondary to hypercapnia. Upon review, the TSH level is low (0.12 mIU/L). A free T4 (FT4) level is ordered and returns mildly low (0.6 ng/dL). Somewhat puzzled, the hospitalist wonders if the patient might have central hypothyroidism and if further testing is needed.

Thyroid disease has a prevalence in adults of 4.6% and 1.3% for hypo- and hyperthyroidism, respectively.¹ Severe manifestations of thyroid disease are rare, with an annual incidence of 0.2 per 100,000² for thyroid storm and 1.08 per 1,000,000³ for myxedema coma in adults. Although most thyroid disease is mild and managed in the outpatient setting, inpatient thyroid testing is common, with evidence suggesting that 21%-100% of internal medicine admissions receive thyroid testing.^4-7

Despite the rarity of severe thyroid disease, symptomatic hypo- or hyperthyroidism is often included in the differential diagnosis for a multitude of presenting problems to the hospital. Providers may view TSH as a simple means to rule out thyroid illness and narrow the diagnostic differential, particularly given the speed and availability of testing. In addition, cultural norms may encourage the routine assessment of thyroid function as a part of a thorough inpatient evaluation, even when alternative diagnoses could explain the patient’s symptoms.⁸ In many hospitals, TSH is included in emergency department laboratory panels and hospital admission order sets (sometimes as a preselected default), which can significantly influence prescriber ordering.^4,6,7,9

Hardwick et al. conducted structured interviews with primary care providers to explore the factors contributing to high thyroid testing variability. Among the potential contributing factors identified were fear of a missed diagnosis, as well as the complexity and poor integration of electronic health records, which makes repeat testing easier than requesting outside records.¹⁰ Most importantly, providers may assume that all abnormal results indicate clinically relevant thyroid dysfunction despite differences between TSH test characteristics in inpatient vs outpatient settings.¹¹

The most important confounder of thyroid function testing in the hospital is nonthyroidal illness syndrome (NTIS), also known as sick euthyroid syndrome. Although the prevalence of unrecognized thyroid disease in hospitalized patients is 1%-2.5%,¹¹ NTIS is observed in up to 62% of hospitalized patients and not exclusively in critically ill patients as previously thought.⁸ Risk factors include infection, stroke, myocardial infarction, kidney or liver injury, burns, malnutrition, malignancy, and recent surgery, as well as multiple medications.¹² Contributing factors may include the effect of cytokines on thyroid-releasing hormone and TSH secretion, decreased deiodinase activity, and changes in thyroid hormone receptor activity.⁸ No one pattern of thyroid function testing is pathognomonic of NTIS.^8,12

The high prevalence of NTIS reduces the specificity of TSH testing in hospitalized patients. In this population, Attia et al. determined that mild abnormalities (TSH 0.1-0.6 mIU/L or 6.7-20 mIU/L) have a positive likelihood ratio (LR+) of true thyroid disease of 0.0 and 0.74, respectively, counterintuitively reducing rather than increasing the posttest probability of thyroid disease. Although TSH levels <0.01 and >20 mIU/L carry a higher LR+ (7.7 and 11.1, respectively), the vast majority of abnormal TSH results in the hospital are mild, self-resolving, and do not change clinical management.^5,11,13 Adlan et al. reported that only 1.2% of tested patients have very abnormal TSH results (4/751 with TSH <0.01 and 5/751 with TSH >10 mIU/L).⁵

Spencer et al. measured TSH and other thyroid function tests in 1,580 adult patients admitted to a large county hospital in the United States, without regard to symptoms or prior diagnosis of thyroid disease. They found that 519/1,580 (33%) had TSH values outside the laboratory reference range. Of the 1,580 patients, 329 were randomly selected for further analysis, and 29/329 (8.8%) were found to have true thyroid disease. The vast majority of these patients (22/29, 75.8%) had TSH levels <0.1 mIU/L or >20 mIU/L. Importantly, the authors did not indicate how many of the 29 patients had known preexisiting thyroid disease or clinical symptoms.¹³

Similarly, an Israeli study examined the utility of routine TSH testing upon admission to an internal medicine service. More than 1 in 10 patients had abnormal TSH results (11.8%, 232/1,966). After chart review, the majority of the abnormal results (52.2%, 121/232) were felt to be secondary to NTIS. Subclinical thyrotoxicosis and subclinical hypothyroidism were noted in a further 20.7% (48/232) and 18.5% (43/232) of the patients, respectively. Overall, in only nine patients (0.5%, 9/1,966) did TSH testing lead to a change in clinical management. In all these cases, patients were either already on a medication known to affect thyroid function (eg, levothyroxine, amiodarone) or the pretest probability of thyroid-related illness was elevated because of clinical presentation.⁴

Several institutions have implemented quality improvement (QI) initiatives to reduce inappropriate thyroid function testing without apparent compromise to clinical care.¹⁴ Although none included balancing measures within their QI design, the implementation of simple appropriateness guidelines, for example, has been shown to reduce the frequency of TSH ordering by as much as 50%, which suggests significant overtesting.^5,15,16 Similarly, in a clustered randomized control trial, Thomas et al. demonstrated a significant reduction (odds ratio [OR] 0.82) in outpatient TSH ordering after the addition of a simple educational message to the order.¹⁷

NTIS may cause TSH, T4, and even FT4 to increase or decrease, even in discordant patterns, such as in the case above. This makes interpretation difficult for the hospitalist, who may wonder about the necessity and timing of further testing. Potential harms include additional unnecessary laboratory testing, inappropriate levothyroxine prescription (potentially leading to iatrogenic hyperthyroidism),¹⁸ and excess specialty referral. The American Association of Clinical Endocrinologists (AACE) and the American Thyroid Association (ATA) guidelines specifically highlight the “cost considerations and potential for inappropriate intervention” associated with TSH testing in the hospital setting.¹⁹

Given the limitations of TSH testing in hospitalized patients due to NTIS, the AACE/ATA recommend TSH measurement in hospitalized patients only in cases of high clinical suspicion for thyroid dysfunction (Grade A, Best Level Evidence 2).¹⁹ The specificity of TSH testing in the hospital setting is too low to justify screening for mild or subclinical disease.⁸ Instead, directed thyroid function testing should be performed for hospitalized patients with sufficient signs and symptoms to raise the pretest probability of a clinically relevant result (Table). According to Attia et al., the total number of signs and symptoms (rather than one particular sign or symptom) may be the most reliable indicator. In two outpatient studies (no inpatient data available), the presence of one to two signs or symptoms of thyroid disease yielded an LR+ of 0.11-0.2, three to four signs or symptoms yielded an LR+ of 0.74-1.14, and five or more signs or symptoms yielded an LR+ of 6.75-18.6.¹¹ For example, if a general medical patient (prevalence of undiagnosed hypothyroidism estimated to be 0.6%) has constipation and fatigue (LR+ 0.2), then the pretest probability would be approximately 0.1%. If the TSH level results between 6.7 and 20 mIU/L (LR+ 0.74), the posttest probability of thyroid disease would remain only 0.1%. Alternatively, a general medical patient with five symptoms consistent with hypothyroidism (LR+ 18.6) would have a pretest probability of 10%. If the TSH level results >20 mIU/L (LR+ 11.1), then the posttest probability of hypothyroidism would be 55%.¹¹

For patients on stable doses of thyroid hormone replacement, although it may seem logical to check a TSH level upon admission to the hospital, guidelines recommend monitoring levels routinely in the outpatient setting, at most once every 12 months. More frequent monitoring should be undertaken only if clinical symptoms suggest that a dose change may be needed,¹⁹ and routine hospital testing should be avoided because of the potential for misleading results.

However, in some specific clinical scenarios, it may be reasonable to test for thyroid disease. Guidelines suggest TSH testing in the evaluation of certain conditions such as atrial fibrillation²⁰ and syndrome of inappropriate antidiuretic hormone (SIADH).²¹ In addition, in the evaluation of unexplained sinus tachycardia, it is reasonable to test for hyperthyroidism after more common causes (pain, anxiety, infection, anemia, drug ingestion, and beta-­blocker withdrawal) have been excluded.²² In the evaluation of delirium, TSH may be an appropriate “second tier” test after more likely contributors have been excluded.²³

• Do not routinely order TSH on admission given the low pretest probability of clinically significant thyroid disease.
• Do not routinely check TSH for inpatients on stable outpatient doses of thyroid hormone replacement.
• Reserve TSH testing for clinical scenarios in which there is either a high pretest probability of thyroid disease (five or more symptoms) or for the evaluation of specific clinical syndromes for which thyroid dysfunction is a known reversible contributor (such as atrial fibrillation, SIADH, unexplained sinus tachycardia, and delirium).
• Do not attempt to diagnose subclinical thyroid disease in the hospital.
• If NTIS is suspected, avoid further testing in the hospital. Repeating TFTs as an outpatient may be appropriate after resolution of the acute illness.

Routine TSH testing in hospitalized patients is unhelpful and often yields confusing results because of the low prevalence of unrecognized thyroid disease, the high prevalence of NTIS, and the resulting difficulty with interpretation of results. Mild TSH abnormalities in hospitalized patients do not predict clinically significant thyroid disease.^4,11 The patient in the previously described clinical scenario has NTIS caused by acute on chronic illness and the effect of glucocorticoids. As the hospitalist suspected, the patient’s AMS was caused by hypercapnia. Reserving TSH testing for patients with clinical signs and symptoms of thyroid disease or for those with specific conditions has the potential to save healthcare dollars, prevent harm to patients associated with overtesting or overtreatment, and decrease time spent interpreting abnormal results of unclear significance.

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason™?” Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason™” topics by emailing TWDFNR@hospitalmedicine.org.

Inspired by the ABIM Foundation’s Choosing Wisely^® campaign, the “Things We Do for No Reason^™” (TWDFNR) series reviews practices that have become common parts of hospital care but may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent clear-cut conclusions or clinical practice standards but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion.

A 62-year-old woman with chronic obstructive pulmonary disease (COPD) presents to the emergency department with shortness of breath, wheezing, and altered mental status (AMS). She is diagnosed with an acute COPD exacerbation with hypercarbic respiratory failure and is treated with nebulized albuterol/ipratropium and intravenous methylprednisolone. The hospitalist orders basic admission laboratory tests, including a thyroid-stimulating hormone (TSH) test for completeness, although she suspects that the patient’s AMS is secondary to hypercapnia. Upon review, the TSH level is low (0.12 mIU/L). A free T4 (FT4) level is ordered and returns mildly low (0.6 ng/dL). Somewhat puzzled, the hospitalist wonders if the patient might have central hypothyroidism and if further testing is needed.

Thyroid disease has a prevalence in adults of 4.6% and 1.3% for hypo- and hyperthyroidism, respectively.¹ Severe manifestations of thyroid disease are rare, with an annual incidence of 0.2 per 100,000² for thyroid storm and 1.08 per 1,000,000³ for myxedema coma in adults. Although most thyroid disease is mild and managed in the outpatient setting, inpatient thyroid testing is common, with evidence suggesting that 21%-100% of internal medicine admissions receive thyroid testing.^4-7

Despite the rarity of severe thyroid disease, symptomatic hypo- or hyperthyroidism is often included in the differential diagnosis for a multitude of presenting problems to the hospital. Providers may view TSH as a simple means to rule out thyroid illness and narrow the diagnostic differential, particularly given the speed and availability of testing. In addition, cultural norms may encourage the routine assessment of thyroid function as a part of a thorough inpatient evaluation, even when alternative diagnoses could explain the patient’s symptoms.⁸ In many hospitals, TSH is included in emergency department laboratory panels and hospital admission order sets (sometimes as a preselected default), which can significantly influence prescriber ordering.^4,6,7,9

Hardwick et al. conducted structured interviews with primary care providers to explore the factors contributing to high thyroid testing variability. Among the potential contributing factors identified were fear of a missed diagnosis, as well as the complexity and poor integration of electronic health records, which makes repeat testing easier than requesting outside records.¹⁰ Most importantly, providers may assume that all abnormal results indicate clinically relevant thyroid dysfunction despite differences between TSH test characteristics in inpatient vs outpatient settings.¹¹

The most important confounder of thyroid function testing in the hospital is nonthyroidal illness syndrome (NTIS), also known as sick euthyroid syndrome. Although the prevalence of unrecognized thyroid disease in hospitalized patients is 1%-2.5%,¹¹ NTIS is observed in up to 62% of hospitalized patients and not exclusively in critically ill patients as previously thought.⁸ Risk factors include infection, stroke, myocardial infarction, kidney or liver injury, burns, malnutrition, malignancy, and recent surgery, as well as multiple medications.¹² Contributing factors may include the effect of cytokines on thyroid-releasing hormone and TSH secretion, decreased deiodinase activity, and changes in thyroid hormone receptor activity.⁸ No one pattern of thyroid function testing is pathognomonic of NTIS.^8,12

The high prevalence of NTIS reduces the specificity of TSH testing in hospitalized patients. In this population, Attia et al. determined that mild abnormalities (TSH 0.1-0.6 mIU/L or 6.7-20 mIU/L) have a positive likelihood ratio (LR+) of true thyroid disease of 0.0 and 0.74, respectively, counterintuitively reducing rather than increasing the posttest probability of thyroid disease. Although TSH levels <0.01 and >20 mIU/L carry a higher LR+ (7.7 and 11.1, respectively), the vast majority of abnormal TSH results in the hospital are mild, self-resolving, and do not change clinical management.^5,11,13 Adlan et al. reported that only 1.2% of tested patients have very abnormal TSH results (4/751 with TSH <0.01 and 5/751 with TSH >10 mIU/L).⁵

Spencer et al. measured TSH and other thyroid function tests in 1,580 adult patients admitted to a large county hospital in the United States, without regard to symptoms or prior diagnosis of thyroid disease. They found that 519/1,580 (33%) had TSH values outside the laboratory reference range. Of the 1,580 patients, 329 were randomly selected for further analysis, and 29/329 (8.8%) were found to have true thyroid disease. The vast majority of these patients (22/29, 75.8%) had TSH levels <0.1 mIU/L or >20 mIU/L. Importantly, the authors did not indicate how many of the 29 patients had known preexisiting thyroid disease or clinical symptoms.¹³

Similarly, an Israeli study examined the utility of routine TSH testing upon admission to an internal medicine service. More than 1 in 10 patients had abnormal TSH results (11.8%, 232/1,966). After chart review, the majority of the abnormal results (52.2%, 121/232) were felt to be secondary to NTIS. Subclinical thyrotoxicosis and subclinical hypothyroidism were noted in a further 20.7% (48/232) and 18.5% (43/232) of the patients, respectively. Overall, in only nine patients (0.5%, 9/1,966) did TSH testing lead to a change in clinical management. In all these cases, patients were either already on a medication known to affect thyroid function (eg, levothyroxine, amiodarone) or the pretest probability of thyroid-related illness was elevated because of clinical presentation.⁴

Several institutions have implemented quality improvement (QI) initiatives to reduce inappropriate thyroid function testing without apparent compromise to clinical care.¹⁴ Although none included balancing measures within their QI design, the implementation of simple appropriateness guidelines, for example, has been shown to reduce the frequency of TSH ordering by as much as 50%, which suggests significant overtesting.^5,15,16 Similarly, in a clustered randomized control trial, Thomas et al. demonstrated a significant reduction (odds ratio [OR] 0.82) in outpatient TSH ordering after the addition of a simple educational message to the order.¹⁷

NTIS may cause TSH, T4, and even FT4 to increase or decrease, even in discordant patterns, such as in the case above. This makes interpretation difficult for the hospitalist, who may wonder about the necessity and timing of further testing. Potential harms include additional unnecessary laboratory testing, inappropriate levothyroxine prescription (potentially leading to iatrogenic hyperthyroidism),¹⁸ and excess specialty referral. The American Association of Clinical Endocrinologists (AACE) and the American Thyroid Association (ATA) guidelines specifically highlight the “cost considerations and potential for inappropriate intervention” associated with TSH testing in the hospital setting.¹⁹

Given the limitations of TSH testing in hospitalized patients due to NTIS, the AACE/ATA recommend TSH measurement in hospitalized patients only in cases of high clinical suspicion for thyroid dysfunction (Grade A, Best Level Evidence 2).¹⁹ The specificity of TSH testing in the hospital setting is too low to justify screening for mild or subclinical disease.⁸ Instead, directed thyroid function testing should be performed for hospitalized patients with sufficient signs and symptoms to raise the pretest probability of a clinically relevant result (Table). According to Attia et al., the total number of signs and symptoms (rather than one particular sign or symptom) may be the most reliable indicator. In two outpatient studies (no inpatient data available), the presence of one to two signs or symptoms of thyroid disease yielded an LR+ of 0.11-0.2, three to four signs or symptoms yielded an LR+ of 0.74-1.14, and five or more signs or symptoms yielded an LR+ of 6.75-18.6.¹¹ For example, if a general medical patient (prevalence of undiagnosed hypothyroidism estimated to be 0.6%) has constipation and fatigue (LR+ 0.2), then the pretest probability would be approximately 0.1%. If the TSH level results between 6.7 and 20 mIU/L (LR+ 0.74), the posttest probability of thyroid disease would remain only 0.1%. Alternatively, a general medical patient with five symptoms consistent with hypothyroidism (LR+ 18.6) would have a pretest probability of 10%. If the TSH level results >20 mIU/L (LR+ 11.1), then the posttest probability of hypothyroidism would be 55%.¹¹

For patients on stable doses of thyroid hormone replacement, although it may seem logical to check a TSH level upon admission to the hospital, guidelines recommend monitoring levels routinely in the outpatient setting, at most once every 12 months. More frequent monitoring should be undertaken only if clinical symptoms suggest that a dose change may be needed,¹⁹ and routine hospital testing should be avoided because of the potential for misleading results.

However, in some specific clinical scenarios, it may be reasonable to test for thyroid disease. Guidelines suggest TSH testing in the evaluation of certain conditions such as atrial fibrillation²⁰ and syndrome of inappropriate antidiuretic hormone (SIADH).²¹ In addition, in the evaluation of unexplained sinus tachycardia, it is reasonable to test for hyperthyroidism after more common causes (pain, anxiety, infection, anemia, drug ingestion, and beta-­blocker withdrawal) have been excluded.²² In the evaluation of delirium, TSH may be an appropriate “second tier” test after more likely contributors have been excluded.²³

• Do not routinely order TSH on admission given the low pretest probability of clinically significant thyroid disease.
• Do not routinely check TSH for inpatients on stable outpatient doses of thyroid hormone replacement.
• Reserve TSH testing for clinical scenarios in which there is either a high pretest probability of thyroid disease (five or more symptoms) or for the evaluation of specific clinical syndromes for which thyroid dysfunction is a known reversible contributor (such as atrial fibrillation, SIADH, unexplained sinus tachycardia, and delirium).
• Do not attempt to diagnose subclinical thyroid disease in the hospital.
• If NTIS is suspected, avoid further testing in the hospital. Repeating TFTs as an outpatient may be appropriate after resolution of the acute illness.

Routine TSH testing in hospitalized patients is unhelpful and often yields confusing results because of the low prevalence of unrecognized thyroid disease, the high prevalence of NTIS, and the resulting difficulty with interpretation of results. Mild TSH abnormalities in hospitalized patients do not predict clinically significant thyroid disease.^4,11 The patient in the previously described clinical scenario has NTIS caused by acute on chronic illness and the effect of glucocorticoids. As the hospitalist suspected, the patient’s AMS was caused by hypercapnia. Reserving TSH testing for patients with clinical signs and symptoms of thyroid disease or for those with specific conditions has the potential to save healthcare dollars, prevent harm to patients associated with overtesting or overtreatment, and decrease time spent interpreting abnormal results of unclear significance.

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason™?” Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason™” topics by emailing TWDFNR@hospitalmedicine.org.

Inspired by the ABIM Foundation’s Choosing Wisely^® campaign, the “Things We Do for No Reason^™” (TWDFNR) series reviews practices that have become common parts of hospital care but may provide little value to our patients. Practices reviewed in the TWDFNR series do not represent clear-cut conclusions or clinical practice standards but are meant as a starting place for research and active discussions among hospitalists and patients. We invite you to be part of that discussion.

A 62-year-old woman with chronic obstructive pulmonary disease (COPD) presents to the emergency department with shortness of breath, wheezing, and altered mental status (AMS). She is diagnosed with an acute COPD exacerbation with hypercarbic respiratory failure and is treated with nebulized albuterol/ipratropium and intravenous methylprednisolone. The hospitalist orders basic admission laboratory tests, including a thyroid-stimulating hormone (TSH) test for completeness, although she suspects that the patient’s AMS is secondary to hypercapnia. Upon review, the TSH level is low (0.12 mIU/L). A free T4 (FT4) level is ordered and returns mildly low (0.6 ng/dL). Somewhat puzzled, the hospitalist wonders if the patient might have central hypothyroidism and if further testing is needed.

Thyroid disease has a prevalence in adults of 4.6% and 1.3% for hypo- and hyperthyroidism, respectively.¹ Severe manifestations of thyroid disease are rare, with an annual incidence of 0.2 per 100,000² for thyroid storm and 1.08 per 1,000,000³ for myxedema coma in adults. Although most thyroid disease is mild and managed in the outpatient setting, inpatient thyroid testing is common, with evidence suggesting that 21%-100% of internal medicine admissions receive thyroid testing.^4-7

Despite the rarity of severe thyroid disease, symptomatic hypo- or hyperthyroidism is often included in the differential diagnosis for a multitude of presenting problems to the hospital. Providers may view TSH as a simple means to rule out thyroid illness and narrow the diagnostic differential, particularly given the speed and availability of testing. In addition, cultural norms may encourage the routine assessment of thyroid function as a part of a thorough inpatient evaluation, even when alternative diagnoses could explain the patient’s symptoms.⁸ In many hospitals, TSH is included in emergency department laboratory panels and hospital admission order sets (sometimes as a preselected default), which can significantly influence prescriber ordering.^4,6,7,9

Hardwick et al. conducted structured interviews with primary care providers to explore the factors contributing to high thyroid testing variability. Among the potential contributing factors identified were fear of a missed diagnosis, as well as the complexity and poor integration of electronic health records, which makes repeat testing easier than requesting outside records.¹⁰ Most importantly, providers may assume that all abnormal results indicate clinically relevant thyroid dysfunction despite differences between TSH test characteristics in inpatient vs outpatient settings.¹¹

The most important confounder of thyroid function testing in the hospital is nonthyroidal illness syndrome (NTIS), also known as sick euthyroid syndrome. Although the prevalence of unrecognized thyroid disease in hospitalized patients is 1%-2.5%,¹¹ NTIS is observed in up to 62% of hospitalized patients and not exclusively in critically ill patients as previously thought.⁸ Risk factors include infection, stroke, myocardial infarction, kidney or liver injury, burns, malnutrition, malignancy, and recent surgery, as well as multiple medications.¹² Contributing factors may include the effect of cytokines on thyroid-releasing hormone and TSH secretion, decreased deiodinase activity, and changes in thyroid hormone receptor activity.⁸ No one pattern of thyroid function testing is pathognomonic of NTIS.^8,12

The high prevalence of NTIS reduces the specificity of TSH testing in hospitalized patients. In this population, Attia et al. determined that mild abnormalities (TSH 0.1-0.6 mIU/L or 6.7-20 mIU/L) have a positive likelihood ratio (LR+) of true thyroid disease of 0.0 and 0.74, respectively, counterintuitively reducing rather than increasing the posttest probability of thyroid disease. Although TSH levels <0.01 and >20 mIU/L carry a higher LR+ (7.7 and 11.1, respectively), the vast majority of abnormal TSH results in the hospital are mild, self-resolving, and do not change clinical management.^5,11,13 Adlan et al. reported that only 1.2% of tested patients have very abnormal TSH results (4/751 with TSH <0.01 and 5/751 with TSH >10 mIU/L).⁵

Spencer et al. measured TSH and other thyroid function tests in 1,580 adult patients admitted to a large county hospital in the United States, without regard to symptoms or prior diagnosis of thyroid disease. They found that 519/1,580 (33%) had TSH values outside the laboratory reference range. Of the 1,580 patients, 329 were randomly selected for further analysis, and 29/329 (8.8%) were found to have true thyroid disease. The vast majority of these patients (22/29, 75.8%) had TSH levels <0.1 mIU/L or >20 mIU/L. Importantly, the authors did not indicate how many of the 29 patients had known preexisiting thyroid disease or clinical symptoms.¹³

Similarly, an Israeli study examined the utility of routine TSH testing upon admission to an internal medicine service. More than 1 in 10 patients had abnormal TSH results (11.8%, 232/1,966). After chart review, the majority of the abnormal results (52.2%, 121/232) were felt to be secondary to NTIS. Subclinical thyrotoxicosis and subclinical hypothyroidism were noted in a further 20.7% (48/232) and 18.5% (43/232) of the patients, respectively. Overall, in only nine patients (0.5%, 9/1,966) did TSH testing lead to a change in clinical management. In all these cases, patients were either already on a medication known to affect thyroid function (eg, levothyroxine, amiodarone) or the pretest probability of thyroid-related illness was elevated because of clinical presentation.⁴

Several institutions have implemented quality improvement (QI) initiatives to reduce inappropriate thyroid function testing without apparent compromise to clinical care.¹⁴ Although none included balancing measures within their QI design, the implementation of simple appropriateness guidelines, for example, has been shown to reduce the frequency of TSH ordering by as much as 50%, which suggests significant overtesting.^5,15,16 Similarly, in a clustered randomized control trial, Thomas et al. demonstrated a significant reduction (odds ratio [OR] 0.82) in outpatient TSH ordering after the addition of a simple educational message to the order.¹⁷

NTIS may cause TSH, T4, and even FT4 to increase or decrease, even in discordant patterns, such as in the case above. This makes interpretation difficult for the hospitalist, who may wonder about the necessity and timing of further testing. Potential harms include additional unnecessary laboratory testing, inappropriate levothyroxine prescription (potentially leading to iatrogenic hyperthyroidism),¹⁸ and excess specialty referral. The American Association of Clinical Endocrinologists (AACE) and the American Thyroid Association (ATA) guidelines specifically highlight the “cost considerations and potential for inappropriate intervention” associated with TSH testing in the hospital setting.¹⁹

Given the limitations of TSH testing in hospitalized patients due to NTIS, the AACE/ATA recommend TSH measurement in hospitalized patients only in cases of high clinical suspicion for thyroid dysfunction (Grade A, Best Level Evidence 2).¹⁹ The specificity of TSH testing in the hospital setting is too low to justify screening for mild or subclinical disease.⁸ Instead, directed thyroid function testing should be performed for hospitalized patients with sufficient signs and symptoms to raise the pretest probability of a clinically relevant result (Table). According to Attia et al., the total number of signs and symptoms (rather than one particular sign or symptom) may be the most reliable indicator. In two outpatient studies (no inpatient data available), the presence of one to two signs or symptoms of thyroid disease yielded an LR+ of 0.11-0.2, three to four signs or symptoms yielded an LR+ of 0.74-1.14, and five or more signs or symptoms yielded an LR+ of 6.75-18.6.¹¹ For example, if a general medical patient (prevalence of undiagnosed hypothyroidism estimated to be 0.6%) has constipation and fatigue (LR+ 0.2), then the pretest probability would be approximately 0.1%. If the TSH level results between 6.7 and 20 mIU/L (LR+ 0.74), the posttest probability of thyroid disease would remain only 0.1%. Alternatively, a general medical patient with five symptoms consistent with hypothyroidism (LR+ 18.6) would have a pretest probability of 10%. If the TSH level results >20 mIU/L (LR+ 11.1), then the posttest probability of hypothyroidism would be 55%.¹¹

For patients on stable doses of thyroid hormone replacement, although it may seem logical to check a TSH level upon admission to the hospital, guidelines recommend monitoring levels routinely in the outpatient setting, at most once every 12 months. More frequent monitoring should be undertaken only if clinical symptoms suggest that a dose change may be needed,¹⁹ and routine hospital testing should be avoided because of the potential for misleading results.

However, in some specific clinical scenarios, it may be reasonable to test for thyroid disease. Guidelines suggest TSH testing in the evaluation of certain conditions such as atrial fibrillation²⁰ and syndrome of inappropriate antidiuretic hormone (SIADH).²¹ In addition, in the evaluation of unexplained sinus tachycardia, it is reasonable to test for hyperthyroidism after more common causes (pain, anxiety, infection, anemia, drug ingestion, and beta-­blocker withdrawal) have been excluded.²² In the evaluation of delirium, TSH may be an appropriate “second tier” test after more likely contributors have been excluded.²³

• Do not routinely order TSH on admission given the low pretest probability of clinically significant thyroid disease.
• Do not routinely check TSH for inpatients on stable outpatient doses of thyroid hormone replacement.
• Reserve TSH testing for clinical scenarios in which there is either a high pretest probability of thyroid disease (five or more symptoms) or for the evaluation of specific clinical syndromes for which thyroid dysfunction is a known reversible contributor (such as atrial fibrillation, SIADH, unexplained sinus tachycardia, and delirium).
• Do not attempt to diagnose subclinical thyroid disease in the hospital.
• If NTIS is suspected, avoid further testing in the hospital. Repeating TFTs as an outpatient may be appropriate after resolution of the acute illness.

Routine TSH testing in hospitalized patients is unhelpful and often yields confusing results because of the low prevalence of unrecognized thyroid disease, the high prevalence of NTIS, and the resulting difficulty with interpretation of results. Mild TSH abnormalities in hospitalized patients do not predict clinically significant thyroid disease.^4,11 The patient in the previously described clinical scenario has NTIS caused by acute on chronic illness and the effect of glucocorticoids. As the hospitalist suspected, the patient’s AMS was caused by hypercapnia. Reserving TSH testing for patients with clinical signs and symptoms of thyroid disease or for those with specific conditions has the potential to save healthcare dollars, prevent harm to patients associated with overtesting or overtreatment, and decrease time spent interpreting abnormal results of unclear significance.

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason™?” Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason™” topics by emailing TWDFNR@hospitalmedicine.org.

Incidental findings create both medical and logistical challenges regarding communication.^1,2 Pulmonary nodules are among the most frequent and medically relevant incidental findings, being noted in up to 8.4% of abdominal computed tomography (CT) scans.³ There are guidelines regarding proper follow-up and management of such incidental pulmonary nodules, but appropriate evidence-based surveillance imaging is often not performed, and many patients remain uninformed. Collins et al.⁴ reported that, before initiation of a standardized protocol, only 17.7% of incidental findings were communicated to patients admitted to the trauma service; after protocol initiation, the rate increased to 32.4%. The hospital discharge summary provides an opportunity to communicate incidental findings to patients and their medical care providers, but Kripalani et al.⁵ raised questions regarding the current completeness and accuracy of discharge summaries, reporting that 65% of discharge summaries omitted relevant diagnostic testing, and 30% omitted a follow-up plan.

We conducted a study to determine how often incidental pulmonary nodules found on abdominal CT are documented in the discharge summary, and to identify factors associated with pulmonary nodule inclusion.

This was a retrospective cohort study of hospitalized patients ≥35 years of age who underwent in-patient abdominal CT between January 1, 2012 and December 31, 2014. Patients were identified by cross-referencing hospital admissions with Current Procedural Terminology (CPT) codes indicating abdominal CT (74176, 74177, 74178, 74160, 74150, 74170). Patients with chest CT (CPT codes 71260, 71250, 71270) during that hospitalization or within 30 days before admission were excluded to ensure that pulmonary nodules were incidental and asymptomatic. The index hospitalization was defined as the first hospitalization during which the patient was diagnosed with an incidental pulmonary nodule on abdominal CT, or the first hospitalization during the study period for patients without pulmonary nodules. All patient charts were manually reviewed, and baseline age, sex, and smoking status data collected.

Radiology reports were electronically screened for the words nodule and nodules and then confirmed through manual review of the full text reports. Nodules described as tiny (without other size description) were assumed to be <4 mm in size, per manual review of a small sample. Nodules were deemed as falling outside the Fleischner Society criteria guidelines (designed for indeterminate pulmonary nodules), and were therefore excluded, if any of seven criteria were met: The nodule was (1) cavitary, (2) associated with a known metastatic disease, (3) associated with a known granulomatous disease, (4) associated with a known inflammatory process, (5) reported likely to represent atelectasis, (6) reported likely to be a lymph node, or (7) previously biopsied.⁴

For each patient with pulmonary nodules, a personal history of cancer was obtained. Nodule size, characteristics, and stability compared with available prior imaging were recorded. Radiology reports were reviewed to determine if pulmonary nodules were mentioned in the summary headings of the reports or in the body of the reports and whether specific follow-up recommendations were provided. Hospital discharge summaries were reviewed for documentation of pulmonary nodule(s) and follow-up recommendations. Discharging service (medical/medical subspecialty, surgical/surgical subspecialty) was noted, along with the patients’ condition at discharge (alive, alive on hospice, deceased).

The frequency of incidental pulmonary nodules on abdominal CT during hospitalization and the frequency of nodules requiring follow-up were reported using a point estimate and corresponding 95% confidence interval (CI). The χ² test was used to compare the frequency of pulmonary nodules across patient groups. In addition, for patients found to have incidental nodules requiring follow-up, the χ² test was used to compare across groups the percentage of patients with discharge documentation of the incidental nodule. In all cases, 2-tailed Ps are reported, with P ≤ 0.05 considered statistically significant.

Between January 1, 2012 and December 31, 2014, 7173 patients ≥35 years old underwent in-patient abdominal CT without concurrent chest CT. Of these patients, 62.2% were ≥60 years old, 50.6% were men, and 45.5% were current or former smokers. Incidental pulmonary nodules were noted in 402 patients (5.6%; 95% CI, 5.1%-6.2%), of whom 68.7% were ≥60 years old, 56.5% were men, and 46.3% were current or former smokers. Increasing age (P = 0.004) and male sex (P = 0.015) were associated with increased frequency of incidental pulmonary nodules, but smoking status (P = 0.586) was not. Of patients with incidental nodules, 71.6% had solitary nodules, and 58.5% had a maximum nodule size of ≤4 mm (Table 1). Based on smoking status, nodule size, and reported size stability, 208 patients (2.9%; 95% CI, 2.5%-3.3%) required follow-up surveillance as per 2005 Fleischner Society guidelines. Among solitary pulmonary nodules requiring further surveillance (n = 147), the mean risk of malignancy based on the Mayo Clinic solitary pulmonary nodule risk calculator was 7.9% (interquartile range, 3.0%-10.5%), with 28% having a malignancy risk of ≥10%.⁶

Of the 208 patients with nodules requiring further surveillance, only 48 (23%) received discharge summaries documenting the nodule; 34 of these summaries included a recommendation for nodule follow-up, with 19 of the recommendations including a time frame for repeat CT. Three factors were positively associated with documentation of the pulmonary nodule in the discharge summary: mention of the pulmonary nodule in the summary headings of the radiology report (P < 0.001), radiologist recommendation for further surveillance (P < 0.001), and medical discharging service (P = 0.016) (Table 2). The highest rate of pulmonary nodule inclusion in the discharge summary (42%) was noted among patients for whom the radiology report included specific recommendations.

The frequency of incidental pulmonary nodules reported on abdominal CT in our study (5.6%) is consistent with frequencies reported in similar studies. Wu et al.⁷ (reviewing 141,406 abdominal CT scans) and Alpert et al.⁸ (reviewing 12,287 abdominal CT scans) reported frequencies of 2.5% and 3%, respectively, while Rinaldi et al.³ (reviewing 243 abdominal CT scans) reported a higher frequency, 8.4%. Variation likely results from patient factors and the individual radiologist’s attention to incidental pulmonary findings. Rinaldi et al. suggested that up to 39% of abdominal CT scans include pulmonary nodules on independent review, raising the possibility of significant underreporting. In our study, we focused on pulmonary nodules included in the radiology report to tailor the relevance of our study to the hospital medicine community. We also included only those incidental nodules falling within the purview of the Fleischner Society criteria in order to analyze only findings with established follow-up guidelines.

The rate of pulmonary nodule documentation in our study was low overall (23%) but consistent with the literature. Collins et al.,⁴ for example, reported that only 17.7% of patients with trauma were notified of incidental CT findings by either the discharge summary or an appropriate specialist consultation. Various contributing factors can be hypothesized. First, incidental pulmonary nodules are discovered largely in the context of evaluation for other symptomatic conditions, which can overshadow their importance. Second, the lack of clear patient-friendly education materials regarding incidental pulmonary nodules can complicate discussions with patients. Third, many electronic health record (EHR) systems cannot automatically pull incidental findings into the discharge summary and instead rely on provider vigilance.

As our study does, the literature highlights the importance of the radiology report in communicating incidental findings. In a review of >1000 pulmonary angiographic CT studies, Blagev et al.⁹ reported an overall follow-up rate of 29% (28/96) among patients with incidental pulmonary nodules, but none of the 12 patients with pulmonary nodules mentioned in the body of the report (rather than in the summary headings) received adequate follow-up. Similarly, in Shuaib et al.,¹⁰ radiology reports that included follow-up recommendations were more likely to change patient treatment than reports without follow-up recommendations (70% vs 2%). However, our data also show that radiologist recommendations alone are insufficient to ensure adequate communication of incidental findings.

The literature regarding the most cost-effective means of addressing this quality gap is limited. Some institutions have integrated their EHR systems to allow radiologists to flag incidental findings for auto-population in a dedicated section of the discharge summary. Although these efforts can be helpful, documentation alone does not save lives without appropriate follow-up and intervention. Some institutions have hired dedicated nursing staff as incidental finding coordinators. For high-risk incidental findings, Sperry et al.¹¹ reported that hiring an incidental findings coordinator helped their level I trauma center achieve nearly complete documentation, patient notification, and confirmation of posthospital follow-up appointments. Such solutions, however, are labor-intensive and still rely on appropriate primary care follow-up.

Strengths of our study include its relatively large size and particular focus on the issues and decisions facing hospital medicine providers. By focusing on incidental pulmonary nodules reported on abdominal CT, and excluding patients with concurrent chest CT, we avoided including patients with symptomatic or previously identified pulmonary findings. Study limitations include the cross-sectional, retrospective design, which did not include follow-up data regarding such outcomes as rates of appropriate follow-up surveillance and subsequent lung cancer diagnoses. Our single-center study findings may not apply to all hospital practice settings, though they are consistent with the literature with comparison data.

Our study results highlight the need for a multidisciplinary systems-based approach to incidental pulmonary nodule documentation, communication, and follow-up surveillance.

Disclosure

Nothing to report.

Incidental findings create both medical and logistical challenges regarding communication.^1,2 Pulmonary nodules are among the most frequent and medically relevant incidental findings, being noted in up to 8.4% of abdominal computed tomography (CT) scans.³ There are guidelines regarding proper follow-up and management of such incidental pulmonary nodules, but appropriate evidence-based surveillance imaging is often not performed, and many patients remain uninformed. Collins et al.⁴ reported that, before initiation of a standardized protocol, only 17.7% of incidental findings were communicated to patients admitted to the trauma service; after protocol initiation, the rate increased to 32.4%. The hospital discharge summary provides an opportunity to communicate incidental findings to patients and their medical care providers, but Kripalani et al.⁵ raised questions regarding the current completeness and accuracy of discharge summaries, reporting that 65% of discharge summaries omitted relevant diagnostic testing, and 30% omitted a follow-up plan.

We conducted a study to determine how often incidental pulmonary nodules found on abdominal CT are documented in the discharge summary, and to identify factors associated with pulmonary nodule inclusion.

This was a retrospective cohort study of hospitalized patients ≥35 years of age who underwent in-patient abdominal CT between January 1, 2012 and December 31, 2014. Patients were identified by cross-referencing hospital admissions with Current Procedural Terminology (CPT) codes indicating abdominal CT (74176, 74177, 74178, 74160, 74150, 74170). Patients with chest CT (CPT codes 71260, 71250, 71270) during that hospitalization or within 30 days before admission were excluded to ensure that pulmonary nodules were incidental and asymptomatic. The index hospitalization was defined as the first hospitalization during which the patient was diagnosed with an incidental pulmonary nodule on abdominal CT, or the first hospitalization during the study period for patients without pulmonary nodules. All patient charts were manually reviewed, and baseline age, sex, and smoking status data collected.

Radiology reports were electronically screened for the words nodule and nodules and then confirmed through manual review of the full text reports. Nodules described as tiny (without other size description) were assumed to be <4 mm in size, per manual review of a small sample. Nodules were deemed as falling outside the Fleischner Society criteria guidelines (designed for indeterminate pulmonary nodules), and were therefore excluded, if any of seven criteria were met: The nodule was (1) cavitary, (2) associated with a known metastatic disease, (3) associated with a known granulomatous disease, (4) associated with a known inflammatory process, (5) reported likely to represent atelectasis, (6) reported likely to be a lymph node, or (7) previously biopsied.⁴

For each patient with pulmonary nodules, a personal history of cancer was obtained. Nodule size, characteristics, and stability compared with available prior imaging were recorded. Radiology reports were reviewed to determine if pulmonary nodules were mentioned in the summary headings of the reports or in the body of the reports and whether specific follow-up recommendations were provided. Hospital discharge summaries were reviewed for documentation of pulmonary nodule(s) and follow-up recommendations. Discharging service (medical/medical subspecialty, surgical/surgical subspecialty) was noted, along with the patients’ condition at discharge (alive, alive on hospice, deceased).

The frequency of incidental pulmonary nodules on abdominal CT during hospitalization and the frequency of nodules requiring follow-up were reported using a point estimate and corresponding 95% confidence interval (CI). The χ² test was used to compare the frequency of pulmonary nodules across patient groups. In addition, for patients found to have incidental nodules requiring follow-up, the χ² test was used to compare across groups the percentage of patients with discharge documentation of the incidental nodule. In all cases, 2-tailed Ps are reported, with P ≤ 0.05 considered statistically significant.

Between January 1, 2012 and December 31, 2014, 7173 patients ≥35 years old underwent in-patient abdominal CT without concurrent chest CT. Of these patients, 62.2% were ≥60 years old, 50.6% were men, and 45.5% were current or former smokers. Incidental pulmonary nodules were noted in 402 patients (5.6%; 95% CI, 5.1%-6.2%), of whom 68.7% were ≥60 years old, 56.5% were men, and 46.3% were current or former smokers. Increasing age (P = 0.004) and male sex (P = 0.015) were associated with increased frequency of incidental pulmonary nodules, but smoking status (P = 0.586) was not. Of patients with incidental nodules, 71.6% had solitary nodules, and 58.5% had a maximum nodule size of ≤4 mm (Table 1). Based on smoking status, nodule size, and reported size stability, 208 patients (2.9%; 95% CI, 2.5%-3.3%) required follow-up surveillance as per 2005 Fleischner Society guidelines. Among solitary pulmonary nodules requiring further surveillance (n = 147), the mean risk of malignancy based on the Mayo Clinic solitary pulmonary nodule risk calculator was 7.9% (interquartile range, 3.0%-10.5%), with 28% having a malignancy risk of ≥10%.⁶

Of the 208 patients with nodules requiring further surveillance, only 48 (23%) received discharge summaries documenting the nodule; 34 of these summaries included a recommendation for nodule follow-up, with 19 of the recommendations including a time frame for repeat CT. Three factors were positively associated with documentation of the pulmonary nodule in the discharge summary: mention of the pulmonary nodule in the summary headings of the radiology report (P < 0.001), radiologist recommendation for further surveillance (P < 0.001), and medical discharging service (P = 0.016) (Table 2). The highest rate of pulmonary nodule inclusion in the discharge summary (42%) was noted among patients for whom the radiology report included specific recommendations.

The frequency of incidental pulmonary nodules reported on abdominal CT in our study (5.6%) is consistent with frequencies reported in similar studies. Wu et al.⁷ (reviewing 141,406 abdominal CT scans) and Alpert et al.⁸ (reviewing 12,287 abdominal CT scans) reported frequencies of 2.5% and 3%, respectively, while Rinaldi et al.³ (reviewing 243 abdominal CT scans) reported a higher frequency, 8.4%. Variation likely results from patient factors and the individual radiologist’s attention to incidental pulmonary findings. Rinaldi et al. suggested that up to 39% of abdominal CT scans include pulmonary nodules on independent review, raising the possibility of significant underreporting. In our study, we focused on pulmonary nodules included in the radiology report to tailor the relevance of our study to the hospital medicine community. We also included only those incidental nodules falling within the purview of the Fleischner Society criteria in order to analyze only findings with established follow-up guidelines.

The rate of pulmonary nodule documentation in our study was low overall (23%) but consistent with the literature. Collins et al.,⁴ for example, reported that only 17.7% of patients with trauma were notified of incidental CT findings by either the discharge summary or an appropriate specialist consultation. Various contributing factors can be hypothesized. First, incidental pulmonary nodules are discovered largely in the context of evaluation for other symptomatic conditions, which can overshadow their importance. Second, the lack of clear patient-friendly education materials regarding incidental pulmonary nodules can complicate discussions with patients. Third, many electronic health record (EHR) systems cannot automatically pull incidental findings into the discharge summary and instead rely on provider vigilance.

As our study does, the literature highlights the importance of the radiology report in communicating incidental findings. In a review of >1000 pulmonary angiographic CT studies, Blagev et al.⁹ reported an overall follow-up rate of 29% (28/96) among patients with incidental pulmonary nodules, but none of the 12 patients with pulmonary nodules mentioned in the body of the report (rather than in the summary headings) received adequate follow-up. Similarly, in Shuaib et al.,¹⁰ radiology reports that included follow-up recommendations were more likely to change patient treatment than reports without follow-up recommendations (70% vs 2%). However, our data also show that radiologist recommendations alone are insufficient to ensure adequate communication of incidental findings.

The literature regarding the most cost-effective means of addressing this quality gap is limited. Some institutions have integrated their EHR systems to allow radiologists to flag incidental findings for auto-population in a dedicated section of the discharge summary. Although these efforts can be helpful, documentation alone does not save lives without appropriate follow-up and intervention. Some institutions have hired dedicated nursing staff as incidental finding coordinators. For high-risk incidental findings, Sperry et al.¹¹ reported that hiring an incidental findings coordinator helped their level I trauma center achieve nearly complete documentation, patient notification, and confirmation of posthospital follow-up appointments. Such solutions, however, are labor-intensive and still rely on appropriate primary care follow-up.

Strengths of our study include its relatively large size and particular focus on the issues and decisions facing hospital medicine providers. By focusing on incidental pulmonary nodules reported on abdominal CT, and excluding patients with concurrent chest CT, we avoided including patients with symptomatic or previously identified pulmonary findings. Study limitations include the cross-sectional, retrospective design, which did not include follow-up data regarding such outcomes as rates of appropriate follow-up surveillance and subsequent lung cancer diagnoses. Our single-center study findings may not apply to all hospital practice settings, though they are consistent with the literature with comparison data.

Our study results highlight the need for a multidisciplinary systems-based approach to incidental pulmonary nodule documentation, communication, and follow-up surveillance.

Disclosure

Nothing to report.

Incidental findings create both medical and logistical challenges regarding communication.^1,2 Pulmonary nodules are among the most frequent and medically relevant incidental findings, being noted in up to 8.4% of abdominal computed tomography (CT) scans.³ There are guidelines regarding proper follow-up and management of such incidental pulmonary nodules, but appropriate evidence-based surveillance imaging is often not performed, and many patients remain uninformed. Collins et al.⁴ reported that, before initiation of a standardized protocol, only 17.7% of incidental findings were communicated to patients admitted to the trauma service; after protocol initiation, the rate increased to 32.4%. The hospital discharge summary provides an opportunity to communicate incidental findings to patients and their medical care providers, but Kripalani et al.⁵ raised questions regarding the current completeness and accuracy of discharge summaries, reporting that 65% of discharge summaries omitted relevant diagnostic testing, and 30% omitted a follow-up plan.

We conducted a study to determine how often incidental pulmonary nodules found on abdominal CT are documented in the discharge summary, and to identify factors associated with pulmonary nodule inclusion.

This was a retrospective cohort study of hospitalized patients ≥35 years of age who underwent in-patient abdominal CT between January 1, 2012 and December 31, 2014. Patients were identified by cross-referencing hospital admissions with Current Procedural Terminology (CPT) codes indicating abdominal CT (74176, 74177, 74178, 74160, 74150, 74170). Patients with chest CT (CPT codes 71260, 71250, 71270) during that hospitalization or within 30 days before admission were excluded to ensure that pulmonary nodules were incidental and asymptomatic. The index hospitalization was defined as the first hospitalization during which the patient was diagnosed with an incidental pulmonary nodule on abdominal CT, or the first hospitalization during the study period for patients without pulmonary nodules. All patient charts were manually reviewed, and baseline age, sex, and smoking status data collected.

Radiology reports were electronically screened for the words nodule and nodules and then confirmed through manual review of the full text reports. Nodules described as tiny (without other size description) were assumed to be <4 mm in size, per manual review of a small sample. Nodules were deemed as falling outside the Fleischner Society criteria guidelines (designed for indeterminate pulmonary nodules), and were therefore excluded, if any of seven criteria were met: The nodule was (1) cavitary, (2) associated with a known metastatic disease, (3) associated with a known granulomatous disease, (4) associated with a known inflammatory process, (5) reported likely to represent atelectasis, (6) reported likely to be a lymph node, or (7) previously biopsied.⁴

For each patient with pulmonary nodules, a personal history of cancer was obtained. Nodule size, characteristics, and stability compared with available prior imaging were recorded. Radiology reports were reviewed to determine if pulmonary nodules were mentioned in the summary headings of the reports or in the body of the reports and whether specific follow-up recommendations were provided. Hospital discharge summaries were reviewed for documentation of pulmonary nodule(s) and follow-up recommendations. Discharging service (medical/medical subspecialty, surgical/surgical subspecialty) was noted, along with the patients’ condition at discharge (alive, alive on hospice, deceased).

The frequency of incidental pulmonary nodules on abdominal CT during hospitalization and the frequency of nodules requiring follow-up were reported using a point estimate and corresponding 95% confidence interval (CI). The χ² test was used to compare the frequency of pulmonary nodules across patient groups. In addition, for patients found to have incidental nodules requiring follow-up, the χ² test was used to compare across groups the percentage of patients with discharge documentation of the incidental nodule. In all cases, 2-tailed Ps are reported, with P ≤ 0.05 considered statistically significant.

Between January 1, 2012 and December 31, 2014, 7173 patients ≥35 years old underwent in-patient abdominal CT without concurrent chest CT. Of these patients, 62.2% were ≥60 years old, 50.6% were men, and 45.5% were current or former smokers. Incidental pulmonary nodules were noted in 402 patients (5.6%; 95% CI, 5.1%-6.2%), of whom 68.7% were ≥60 years old, 56.5% were men, and 46.3% were current or former smokers. Increasing age (P = 0.004) and male sex (P = 0.015) were associated with increased frequency of incidental pulmonary nodules, but smoking status (P = 0.586) was not. Of patients with incidental nodules, 71.6% had solitary nodules, and 58.5% had a maximum nodule size of ≤4 mm (Table 1). Based on smoking status, nodule size, and reported size stability, 208 patients (2.9%; 95% CI, 2.5%-3.3%) required follow-up surveillance as per 2005 Fleischner Society guidelines. Among solitary pulmonary nodules requiring further surveillance (n = 147), the mean risk of malignancy based on the Mayo Clinic solitary pulmonary nodule risk calculator was 7.9% (interquartile range, 3.0%-10.5%), with 28% having a malignancy risk of ≥10%.⁶

Of the 208 patients with nodules requiring further surveillance, only 48 (23%) received discharge summaries documenting the nodule; 34 of these summaries included a recommendation for nodule follow-up, with 19 of the recommendations including a time frame for repeat CT. Three factors were positively associated with documentation of the pulmonary nodule in the discharge summary: mention of the pulmonary nodule in the summary headings of the radiology report (P < 0.001), radiologist recommendation for further surveillance (P < 0.001), and medical discharging service (P = 0.016) (Table 2). The highest rate of pulmonary nodule inclusion in the discharge summary (42%) was noted among patients for whom the radiology report included specific recommendations.

The frequency of incidental pulmonary nodules reported on abdominal CT in our study (5.6%) is consistent with frequencies reported in similar studies. Wu et al.⁷ (reviewing 141,406 abdominal CT scans) and Alpert et al.⁸ (reviewing 12,287 abdominal CT scans) reported frequencies of 2.5% and 3%, respectively, while Rinaldi et al.³ (reviewing 243 abdominal CT scans) reported a higher frequency, 8.4%. Variation likely results from patient factors and the individual radiologist’s attention to incidental pulmonary findings. Rinaldi et al. suggested that up to 39% of abdominal CT scans include pulmonary nodules on independent review, raising the possibility of significant underreporting. In our study, we focused on pulmonary nodules included in the radiology report to tailor the relevance of our study to the hospital medicine community. We also included only those incidental nodules falling within the purview of the Fleischner Society criteria in order to analyze only findings with established follow-up guidelines.

The rate of pulmonary nodule documentation in our study was low overall (23%) but consistent with the literature. Collins et al.,⁴ for example, reported that only 17.7% of patients with trauma were notified of incidental CT findings by either the discharge summary or an appropriate specialist consultation. Various contributing factors can be hypothesized. First, incidental pulmonary nodules are discovered largely in the context of evaluation for other symptomatic conditions, which can overshadow their importance. Second, the lack of clear patient-friendly education materials regarding incidental pulmonary nodules can complicate discussions with patients. Third, many electronic health record (EHR) systems cannot automatically pull incidental findings into the discharge summary and instead rely on provider vigilance.

As our study does, the literature highlights the importance of the radiology report in communicating incidental findings. In a review of >1000 pulmonary angiographic CT studies, Blagev et al.⁹ reported an overall follow-up rate of 29% (28/96) among patients with incidental pulmonary nodules, but none of the 12 patients with pulmonary nodules mentioned in the body of the report (rather than in the summary headings) received adequate follow-up. Similarly, in Shuaib et al.,¹⁰ radiology reports that included follow-up recommendations were more likely to change patient treatment than reports without follow-up recommendations (70% vs 2%). However, our data also show that radiologist recommendations alone are insufficient to ensure adequate communication of incidental findings.

The literature regarding the most cost-effective means of addressing this quality gap is limited. Some institutions have integrated their EHR systems to allow radiologists to flag incidental findings for auto-population in a dedicated section of the discharge summary. Although these efforts can be helpful, documentation alone does not save lives without appropriate follow-up and intervention. Some institutions have hired dedicated nursing staff as incidental finding coordinators. For high-risk incidental findings, Sperry et al.¹¹ reported that hiring an incidental findings coordinator helped their level I trauma center achieve nearly complete documentation, patient notification, and confirmation of posthospital follow-up appointments. Such solutions, however, are labor-intensive and still rely on appropriate primary care follow-up.

Strengths of our study include its relatively large size and particular focus on the issues and decisions facing hospital medicine providers. By focusing on incidental pulmonary nodules reported on abdominal CT, and excluding patients with concurrent chest CT, we avoided including patients with symptomatic or previously identified pulmonary findings. Study limitations include the cross-sectional, retrospective design, which did not include follow-up data regarding such outcomes as rates of appropriate follow-up surveillance and subsequent lung cancer diagnoses. Our single-center study findings may not apply to all hospital practice settings, though they are consistent with the literature with comparison data.

Our study results highlight the need for a multidisciplinary systems-based approach to incidental pulmonary nodule documentation, communication, and follow-up surveillance.

Disclosure

Nothing to report.