Prevention of hip fractures through screening for osteoporosis: A cohort study

Abstract

Background and purpose: Guidelines disagree on who should be screened for osteoporosis, in part due to lack of direct evidence for the effectiveness of screening. The objective of this study was to determine if population-based screening for osteoporosis in older adults is associated with fewer incident hip fractures compared to usual primary care. Methods: We conducted a non-concurrent cohort study of 3107 adults over age 65 who lived in four U.S. communities enrolled in the Cardiovascular Health Study. Participants were randomly selected from Medicare eligibility lists. We included those who came to their study visits in 1994–95 and excluded those with a history of osteoporosis, hip fracture or bisphosphonate use. In that year, participants in 2 of the 4 communities were offered bone density scans, and the results of these tests were given to the participants and their primary care providers. In the other 2 communities, participants received usual primary care. The two groups (those screened by the study and those receiving usual care) were followed for up to 6 years for the outcome of incident hip fracture, which was abstracted from medical records. Variables considered as potential confounders included demographic variables, medical problems, medications, and physical exam findings. Survival analysis and Cox proportional hazards models were used to compare time to first hip fracture in the screened and usual care groups. Results: Of 1422 eligible participants offered scans, 97% completed them. There were 33 incident hip fractures in the screened group (n=1422 people) and 69 incident hip fractures in the usual care group (n=1685 people; p<0.01). At the end of 6 years, the cumulative incidence of hip fractures in the screened group was 3.0%, compared to 5.0% in the usual care group (p<0.01). The unadjusted relative hazard of having a first hip fracture was significantly lower in the screened group (HR 0.59, 95% CI 0.39–0.89). Screening was still associated with a significantly lower hazard of hip fracture after adjustment for gender, age, race-ethnicity, education, self-reported health status, body weight, exercise, walking speed, cognitive function and oral steroid use (HR 0.58, 95% CI 0.35–0.97). Conclusion: Screening for osteoporosis was associated with 40% fewer incident hip fractures over 6 years, compared to usual primary care. Although this study was not randomized, these data suggest that screening for osteoporosis maybe beneficial for community-dwelling women and men over age 65.