BACKGROUND: Various interventions to prevent hip fractures have been tested with mediocre success. Most have treated underlying risk factors, such as osteoporosis and fall propensity. This study evaluated the effectiveness of an external hip protector to prevent hip fractures.

POPULATION STUDIED: The trial involved 1801 ambulatory but frail elderly adults (1409 women and 392 men, mean age=82 years) from 22 community-based health care centers in Finland. All patients were aged at least 70 years, were ambulatory (assisted or unassisted), and had at least one identifiable risk factor for hip fracture.

STUDY DESIGN AND VALIDITY: Patients were randomized using adequate concealment of allocation, in an unblinded manner, to receive a hip protector or to not receive one. The hip protector (KPH Hip Protector, Respecta, Helsinki, Finland) covered the greater trochanter, was 19 cm × 9 cm with a convex shape. It was designed to shunt the energy of an impact away from the greater trochanter, the most common site of hip fracture. The 2 padded protectors were worn inside pockets of a stretchy undergarment and did not limit walking or sitting. The subjects in the hip protector group were asked to wear the protector whenever they were on their feet and especially when they were at risk for falling. Many patients randomized to receive the hip protector (204 of 650) refused to participate. The dropout rate during the 18-month study period was high (657 out of 1427), mostly because of death, inability to walk, or refusal to continue in the study. The subjects from a waiting list replaced the dropouts. The sample size was sufficient to identify a 50% reduction in hip fractures over 1 year. As a group, hip protector subjects had significantly more risk factors for falls. However, statistical adjustment for baseline differences did not alter the results. The authors compensated for the high dropout rate by using an intention-to-treat analysis and including the subjects in the analysis for the time period of participation. Information on other factors associated with hip fractures (race, presence of osteoporosis, and use of osteoporosis medications) would have been helpful for generalizing the results to US patients.

OUTCOMES MEASURED: The primary outcome was hip fracture. Secondary outcome variables were the number and rate of falls in the hip protector group and the number of days the subjects wore the protector.

RESULTS: During follow-up, 13 subjects in the hip protector group had a hip fracture compared with 67 controls. Hip fracture risk was significantly lower in the treatment group (21.3 vs 46.0 per 1000 person-years; relative hazard 0.4; 95% confidence interval [CI], 0.2-0.8; P=.008). The risk of other fractures was similar in the 2 groups, which supports the effectiveness of the hip protector (ie, these patients were not at risk for fractures in general). Subjects in the hip protector group wore them during 48% of all days and during 74% of all falls, suggesting that they were being worn during higher risk times. In the hip protector group, 4 subjects had a hip fracture while wearing the device; 9 subjects had a hip fracture while not wearing it (P=.002). A total of 41 people would have to wear a hip protector for 1 year to prevent one hip fracture (95% CI, 25-115).

BACKGROUND: Various interventions to prevent hip fractures have been tested with mediocre success. Most have treated underlying risk factors, such as osteoporosis and fall propensity. This study evaluated the effectiveness of an external hip protector to prevent hip fractures.

POPULATION STUDIED: The trial involved 1801 ambulatory but frail elderly adults (1409 women and 392 men, mean age=82 years) from 22 community-based health care centers in Finland. All patients were aged at least 70 years, were ambulatory (assisted or unassisted), and had at least one identifiable risk factor for hip fracture.

STUDY DESIGN AND VALIDITY: Patients were randomized using adequate concealment of allocation, in an unblinded manner, to receive a hip protector or to not receive one. The hip protector (KPH Hip Protector, Respecta, Helsinki, Finland) covered the greater trochanter, was 19 cm × 9 cm with a convex shape. It was designed to shunt the energy of an impact away from the greater trochanter, the most common site of hip fracture. The 2 padded protectors were worn inside pockets of a stretchy undergarment and did not limit walking or sitting. The subjects in the hip protector group were asked to wear the protector whenever they were on their feet and especially when they were at risk for falling. Many patients randomized to receive the hip protector (204 of 650) refused to participate. The dropout rate during the 18-month study period was high (657 out of 1427), mostly because of death, inability to walk, or refusal to continue in the study. The subjects from a waiting list replaced the dropouts. The sample size was sufficient to identify a 50% reduction in hip fractures over 1 year. As a group, hip protector subjects had significantly more risk factors for falls. However, statistical adjustment for baseline differences did not alter the results. The authors compensated for the high dropout rate by using an intention-to-treat analysis and including the subjects in the analysis for the time period of participation. Information on other factors associated with hip fractures (race, presence of osteoporosis, and use of osteoporosis medications) would have been helpful for generalizing the results to US patients.

OUTCOMES MEASURED: The primary outcome was hip fracture. Secondary outcome variables were the number and rate of falls in the hip protector group and the number of days the subjects wore the protector.

RESULTS: During follow-up, 13 subjects in the hip protector group had a hip fracture compared with 67 controls. Hip fracture risk was significantly lower in the treatment group (21.3 vs 46.0 per 1000 person-years; relative hazard 0.4; 95% confidence interval [CI], 0.2-0.8; P=.008). The risk of other fractures was similar in the 2 groups, which supports the effectiveness of the hip protector (ie, these patients were not at risk for fractures in general). Subjects in the hip protector group wore them during 48% of all days and during 74% of all falls, suggesting that they were being worn during higher risk times. In the hip protector group, 4 subjects had a hip fracture while wearing the device; 9 subjects had a hip fracture while not wearing it (P=.002). A total of 41 people would have to wear a hip protector for 1 year to prevent one hip fracture (95% CI, 25-115).

BACKGROUND: Various interventions to prevent hip fractures have been tested with mediocre success. Most have treated underlying risk factors, such as osteoporosis and fall propensity. This study evaluated the effectiveness of an external hip protector to prevent hip fractures.

POPULATION STUDIED: The trial involved 1801 ambulatory but frail elderly adults (1409 women and 392 men, mean age=82 years) from 22 community-based health care centers in Finland. All patients were aged at least 70 years, were ambulatory (assisted or unassisted), and had at least one identifiable risk factor for hip fracture.

STUDY DESIGN AND VALIDITY: Patients were randomized using adequate concealment of allocation, in an unblinded manner, to receive a hip protector or to not receive one. The hip protector (KPH Hip Protector, Respecta, Helsinki, Finland) covered the greater trochanter, was 19 cm × 9 cm with a convex shape. It was designed to shunt the energy of an impact away from the greater trochanter, the most common site of hip fracture. The 2 padded protectors were worn inside pockets of a stretchy undergarment and did not limit walking or sitting. The subjects in the hip protector group were asked to wear the protector whenever they were on their feet and especially when they were at risk for falling. Many patients randomized to receive the hip protector (204 of 650) refused to participate. The dropout rate during the 18-month study period was high (657 out of 1427), mostly because of death, inability to walk, or refusal to continue in the study. The subjects from a waiting list replaced the dropouts. The sample size was sufficient to identify a 50% reduction in hip fractures over 1 year. As a group, hip protector subjects had significantly more risk factors for falls. However, statistical adjustment for baseline differences did not alter the results. The authors compensated for the high dropout rate by using an intention-to-treat analysis and including the subjects in the analysis for the time period of participation. Information on other factors associated with hip fractures (race, presence of osteoporosis, and use of osteoporosis medications) would have been helpful for generalizing the results to US patients.

OUTCOMES MEASURED: The primary outcome was hip fracture. Secondary outcome variables were the number and rate of falls in the hip protector group and the number of days the subjects wore the protector.

RESULTS: During follow-up, 13 subjects in the hip protector group had a hip fracture compared with 67 controls. Hip fracture risk was significantly lower in the treatment group (21.3 vs 46.0 per 1000 person-years; relative hazard 0.4; 95% confidence interval [CI], 0.2-0.8; P=.008). The risk of other fractures was similar in the 2 groups, which supports the effectiveness of the hip protector (ie, these patients were not at risk for fractures in general). Subjects in the hip protector group wore them during 48% of all days and during 74% of all falls, suggesting that they were being worn during higher risk times. In the hip protector group, 4 subjects had a hip fracture while wearing the device; 9 subjects had a hip fracture while not wearing it (P=.002). A total of 41 people would have to wear a hip protector for 1 year to prevent one hip fracture (95% CI, 25-115).

BACKGROUND: Many physicians reduce the dose of allergen immunotherapy when patients have significant local reactions to their allergy shots, believing that these patients are at higher risk for systemic reactions. This dose reduction is made despite the fact that the World Health Organization stated in a position paper on allergen immunotherapy that local reactions are not predictive of subsequent systemic reactions.

POPULATION STUDIED: This study was conducted at a single-site Air Force allergy clinic. During the 18-month study period 12,926 allergy shots were given. No further demographic details were provided.

STUDY DESIGN AND VALIDITY: This nonconcurrent cohort study compared reaction rates to allergy shots for 9 months (October 1996 to June 1997) before an intervention with reaction rates for the 9 months (October 1997 to June 1998) after the intervention. The first group (8076 injections) had their allergy shot dose reduced if they had an immediate local reaction 20 mm or larger or if they had any localized swelling that persisted more than 12 hours. The second group (4850 injections) had no dose reduction for immediate and local reactions unless the reaction was larger than the patient’s hand (adult=8-10 cm) or caused the patient significant discomfort. In most respects the study groups can be considered similar. In fact, in many instances the same subject was probably included in both groups (because most patients receive allergy shots for several years they would have been captured in both 9-month study periods). The potential for differences in the study groups comes from selection bias and those lost to follow-up. The first 9-month period included 8076 injections, while the second 9-month period had only 4850 injections. The authors state that this is because there was difficulty getting extract during the second 9-month period, which delayed the initiation of immunotherapy for some. Because allergy shots can be grouped into 2 phases (build-up and maintenance) and the traditional teaching is that reactions are less common in patients getting maintenance shots, the second group may have had a higher proportion receiving the less-risky maintenance injections. The follow-up of both groups was by review of clinic records, of which 74% were located for the first group and 78% for the second group. Bias could be introduced if the patients who were lost to follow-up were significantly different.

OUTCOMES MEASURED: Systemic reaction rates during the 2 periods were determined. Among those with a systemic reaction, the number of times a local reaction immediately preceded the systemic reaction and the total number of previous local reactions were also determined.

RESULTS: Systemic reaction rates were not statistically different during the 2 9-month periods (0.8% before vs 1.0% after, P=.24). The number of times a local reaction preceded a systemic reaction in the first period was not significantly different from the second 9-month period (18.8% before vs 10.5% after, P=.37). The total local reaction rate for those with systemic reactions was not significantly different during the 2 study periods (7.3% before vs 4.7% after, P=.07). The calculated sensitivity for a local reaction predicting a systemic reaction at the next dose was 15% with a positive predictive value of a local reaction for a subsequent systemic reaction of 17%.

BACKGROUND: Many physicians reduce the dose of allergen immunotherapy when patients have significant local reactions to their allergy shots, believing that these patients are at higher risk for systemic reactions. This dose reduction is made despite the fact that the World Health Organization stated in a position paper on allergen immunotherapy that local reactions are not predictive of subsequent systemic reactions.

POPULATION STUDIED: This study was conducted at a single-site Air Force allergy clinic. During the 18-month study period 12,926 allergy shots were given. No further demographic details were provided.

STUDY DESIGN AND VALIDITY: This nonconcurrent cohort study compared reaction rates to allergy shots for 9 months (October 1996 to June 1997) before an intervention with reaction rates for the 9 months (October 1997 to June 1998) after the intervention. The first group (8076 injections) had their allergy shot dose reduced if they had an immediate local reaction 20 mm or larger or if they had any localized swelling that persisted more than 12 hours. The second group (4850 injections) had no dose reduction for immediate and local reactions unless the reaction was larger than the patient’s hand (adult=8-10 cm) or caused the patient significant discomfort. In most respects the study groups can be considered similar. In fact, in many instances the same subject was probably included in both groups (because most patients receive allergy shots for several years they would have been captured in both 9-month study periods). The potential for differences in the study groups comes from selection bias and those lost to follow-up. The first 9-month period included 8076 injections, while the second 9-month period had only 4850 injections. The authors state that this is because there was difficulty getting extract during the second 9-month period, which delayed the initiation of immunotherapy for some. Because allergy shots can be grouped into 2 phases (build-up and maintenance) and the traditional teaching is that reactions are less common in patients getting maintenance shots, the second group may have had a higher proportion receiving the less-risky maintenance injections. The follow-up of both groups was by review of clinic records, of which 74% were located for the first group and 78% for the second group. Bias could be introduced if the patients who were lost to follow-up were significantly different.

OUTCOMES MEASURED: Systemic reaction rates during the 2 periods were determined. Among those with a systemic reaction, the number of times a local reaction immediately preceded the systemic reaction and the total number of previous local reactions were also determined.

RESULTS: Systemic reaction rates were not statistically different during the 2 9-month periods (0.8% before vs 1.0% after, P=.24). The number of times a local reaction preceded a systemic reaction in the first period was not significantly different from the second 9-month period (18.8% before vs 10.5% after, P=.37). The total local reaction rate for those with systemic reactions was not significantly different during the 2 study periods (7.3% before vs 4.7% after, P=.07). The calculated sensitivity for a local reaction predicting a systemic reaction at the next dose was 15% with a positive predictive value of a local reaction for a subsequent systemic reaction of 17%.

BACKGROUND: Many physicians reduce the dose of allergen immunotherapy when patients have significant local reactions to their allergy shots, believing that these patients are at higher risk for systemic reactions. This dose reduction is made despite the fact that the World Health Organization stated in a position paper on allergen immunotherapy that local reactions are not predictive of subsequent systemic reactions.

POPULATION STUDIED: This study was conducted at a single-site Air Force allergy clinic. During the 18-month study period 12,926 allergy shots were given. No further demographic details were provided.

STUDY DESIGN AND VALIDITY: This nonconcurrent cohort study compared reaction rates to allergy shots for 9 months (October 1996 to June 1997) before an intervention with reaction rates for the 9 months (October 1997 to June 1998) after the intervention. The first group (8076 injections) had their allergy shot dose reduced if they had an immediate local reaction 20 mm or larger or if they had any localized swelling that persisted more than 12 hours. The second group (4850 injections) had no dose reduction for immediate and local reactions unless the reaction was larger than the patient’s hand (adult=8-10 cm) or caused the patient significant discomfort. In most respects the study groups can be considered similar. In fact, in many instances the same subject was probably included in both groups (because most patients receive allergy shots for several years they would have been captured in both 9-month study periods). The potential for differences in the study groups comes from selection bias and those lost to follow-up. The first 9-month period included 8076 injections, while the second 9-month period had only 4850 injections. The authors state that this is because there was difficulty getting extract during the second 9-month period, which delayed the initiation of immunotherapy for some. Because allergy shots can be grouped into 2 phases (build-up and maintenance) and the traditional teaching is that reactions are less common in patients getting maintenance shots, the second group may have had a higher proportion receiving the less-risky maintenance injections. The follow-up of both groups was by review of clinic records, of which 74% were located for the first group and 78% for the second group. Bias could be introduced if the patients who were lost to follow-up were significantly different.

OUTCOMES MEASURED: Systemic reaction rates during the 2 periods were determined. Among those with a systemic reaction, the number of times a local reaction immediately preceded the systemic reaction and the total number of previous local reactions were also determined.

RESULTS: Systemic reaction rates were not statistically different during the 2 9-month periods (0.8% before vs 1.0% after, P=.24). The number of times a local reaction preceded a systemic reaction in the first period was not significantly different from the second 9-month period (18.8% before vs 10.5% after, P=.37). The total local reaction rate for those with systemic reactions was not significantly different during the 2 study periods (7.3% before vs 4.7% after, P=.07). The calculated sensitivity for a local reaction predicting a systemic reaction at the next dose was 15% with a positive predictive value of a local reaction for a subsequent systemic reaction of 17%.