Statistical Analysis
All continuous variables are reported as mean ± standard deviation. Data analysis for significance was performed using a Student t test for continuous variables and a χ2 test (or Fisher exact test) for categorical variables in R Foundation for Statistical Computing version 3.1.0. All samples were 2-tailed. A P value < .05 was considered statistically significant. Using the smaller of the 2 study populations, the investigators calculated that the given sample size of 88 in each group would provide 99% power to detect a 2-day difference in the primary endpoint at a 2-sided significance level of 5%.
Results
During the baseline assessment (group 1), 192 cases were reviewed with 103 meeting the inclusion criteria. Group 1 consisted of 85 cases of CAP and 18 cases of HCAP (mean age, 70.7 years). During the follow-up assessment (group 2), 168 cases were reviewed with 88 meeting the inclusion criteria. Group 2 consisted of 68 cases of CAP and 20 cases of HCAP (mean age, 70.8 years).
There was no difference in inpatient mortality rates between groups (3.1% vs 3.0%, P = .99). This mortality rate is consistent with published reports.23 Empiric antibiotic selection was appropriate because there were no exclusions for drug/pathogen mismatch. Pneumonia severity was similar in both groups (Table).
The total duration of antibiotic treatment decreased significantly for CAP and HCAP (Figure). The observed median treatment days for groups 1 and 2 were 11 days and 8 days, respectively. Outpatient antibiotic days also decreased. Mean LOS was shorter in the follow-up group (4.9 ± 2.6 days vs 4.0 ± 2.6 days, P = .02). Length of IV antibiotic duration decreased. Oral antibiotic days while inpatient were not statistically different (1.5 ± 1.8 days vs 1.1 ± 1.5 days, P = .15). During the follow-up period, 26 stewardship notes were entered into CPRS; antibiotics were stopped in 65% of cases.
There were no recorded cases of CDI in either group. There were eleven 28-day readmissions in group 1, only 3 of which were due to infectious causes. One patient had a primary diagnosis of necrotizing pneumonia, 1 had Pseudomonas pneumonia, and 1 patient had a new lung mass and was diagnosed with postobstructive pneumonia. Of eight 28-day readmissions in group 2, only 2 resulted from infectious causes. One readmission primary diagnosis was sinusitis and 1 was recurrent pneumonia (of note, this patient received a 10-day treatment course for pneumonia on initial admission). Two patients died within 28 days of discharge in each group.
Discussion
Other multifaceted single-center interventions have been shown to be effective in large, teaching hospitals,24,25 and it has been suggested that smaller, rural hospitals may be underserved in antimicrobial stewardship activities.26,27 In the global struggle with antimicrobial resistance, McGregor and colleagues highlighted the importance of evaluating successful stewardship methods in an array of clinical settings to help tailor an approach for a specific type of facility.28 To the authors knowledge, this is the first publication showing efficacy of such antimicrobial stewardship interventions specific to pneumonia therapy in a small, primary facility.
The intervention methods used at VHSO are supported by recent IDSA and Society for Healthcare Epidemiology of America guidelines for effective stewardship implementation.29 Prospective audit and feedback is considered a core recommendation, whereas didactic education is recommended only in conjunction with other stewardship activities. Additionally, the guidelines recommend evaluating specific infectious disease syndromes, in this case uncomplicated pneumonia, to focus on specific treatment guidelines. Last, the results of the 3-part intervention can be used to aid in demonstrating facility improvement and encourage continued success.
Of note, VHSO has had established inpatient and outpatient clinical pharmacy roles for several years. Stewardship interventions already in place included an intravenous-to-oral antibiotic switch policy, automatic antibiotic stop dates, as well as pharmacist-driven vancomycin and aminoglycoside dosing. Prior to this multifaceted intervention specific to pneumonia duration, prospective audit and feedback interventions (verbal and written) also were common. The number of interventions specific to this study outside of the stewardship note was not recorded. Using rapid diagnostic testing and biomarkers to aid in stewardship activities at VHSO have been considered, but these tools are not available due to a lab personnel shortage.
Soliciting feedback from providers on their preferred stewardship strategy and perceived barriers was a key component of the educational intervention. Of equal importance was presenting providers with their baseline prescribing data to provide objective evidence of a problem. While all were familiar with existing treatment guidelines, some feedback indicated that it can be difficult to determine accurate antibiotic duration in CPRS. Prescribers reported that identifying antibiotic duration was especially challenging when antibiotics as well as providers change during an admission. Also frequently overlooked were antibiotics given in the emergency department. This could be a key area for clinical pharmacists’ intervention given their familiarity with the CPRS medication sections.
Charani and colleagues suggest that recognizing barriers to implementing best practices and adapting to the local facility culture is paramount for changing prescribing behaviors and developing a successful stewardship intervention.30 At VHSO, the providers were presented with multiple stewardship options but agreed to the new note and template. This process gave providers a voice in selecting their own stewardship intervention. In a culture with no infectious disease physician to champion initiatives, the investigators felt that provider involvement in the intervention selection was unique and may have encouraged provider concurrence.
Although not directly targeted by the intervention strategies, average LOS was shorter in the follow-up group. According to investigators, frequent reminders of clinical stability in the stewardship notes may have influenced this. Even though the note was used only in patients who remained hospitalized for their entire treatment course, investigators felt that it still served as a reminder for prescribing habits as they were also able to show a decrease in outpatient prescription duration.