Validity of self-report for fractures among a multiethnic cohort of postmenopausal women: results from the Women's Health Initiative observational study and clinical trials.

OBJECTIVE

The purpose of this study is to examine the validity of, and factors associated with, the accuracy of self-report (participant-report and proxy-report) for fractures.

DESIGN

Study participants were from the Women's Health Initiative Clinical Trial and Observational Study cohorts. All women were postmenopausal; populations included American Indian, Asian/Pacific Islander, black, Hispanic, and non-Hispanic white. The average length of follow-up was 4.3 years. Self-reported fractures were adjudicated by reviewing medical records. The first adjudicated self-report of fractures for each participant was included in the analysis (n = 6,652).

RESULTS

We found substantial variations in validity of self-report by the fracture site. Agreements between self-reports for single-site fractures and medical records were high for hip (78%) and forearm/wrist (81%) but relatively lower for clinical spine fractures (51%). The average confirmation rate for all single-site fractures was 71%. Misidentification of fracture sites by participants or proxy-reporters seemed to be a cause of unconfirmed self-reports. Higher confirmation rates were observed in participant-reports than in proxy-reports. Results of the multivariate analysis indicated that multiple factors, such as ethnicity, a history of osteoporosis or fractures, body mass index, years since menopause, smoking status, and number of falls in the past year were significantly (P < 0.05) related to the validity of self-report.

CONCLUSION

The validity of self-reports for fracture varies by fracture sites and many other factors. The assessed validity in this study is likely conservative because some of the unconfirmed self-reports may be due to poor medical record systems. The validity of self-reports for hip and forearm/wrist fractures is high in this study, supporting their use in epidemiological studies among postmenopausal women.