Validity of Self-Report of Fractures: Results from a Prospective Study in Men and Women Across Europe

Abstract

In population-based studies of osteoporosis, ascertainment of fractures is typically based on self-report, with subsequent verification by medical records. The aim of this analysis was to assess the validity of self-report of incident nonspine fractures using a postal questionnaire. The degree of overreporting of fracture (false positives) was assessed by comparing self-reports of new fracture from respondents in the multicenter European Prospective Osteoporosis Study with data from other sources including radiographs and medical records. In the analysis, 563 subjects reported nonspine fractures. Verification of the presence of fracture was possible in 510 subjects. Of these, fractures were not confirmed in 11% (false positives). The percentage of false positives was greater in men than in women (15% vs 9%, p = 0.04), and less for fractures of the distal forearm and hip than for fractures at other sites. In a separate study, the degree of underreporting (false negatives) was assessed by follow-up of 251 individuals with confirmed fracture ascertained from the records of fracture clinics in three European centers (Lubeck, Oviedo, Warsaw). Questionnaire responses were received from 174 (69%) subjects. Of these, 12 (7%) did not recall sustaining a fracture (false negatives). The percentage of false negatives was lower for hip and distal forearm fractures with only 3 of 90 (3%) such fractures not recalled. Using the combined data from both studies, of those who reported a 'date' of fracture on the questionnaire, 91% of subjects were correct to within 1 month of the actual date of the fracture. A postal questionnaire is a relatively simple and accurate method for obtaining information about the occurrence of hip and distal forearm fractures, including their timing. Accuracy of ascertainment of fractures at other sites is less good and where possible self-reported fractures at such sites should be verified from other sources.

Prevalent fractures are related to cortical bone geometry in young healthy men at age of peak bone mass

“…Under-and overreporting can occur owing to poor recall. (44) However, our fracture incidence corresponds to published data, (2) and the accuracy for self-report of fractures was found to be good in postmenopausal women for forearm or hip fractures. (45) Moreover, imprecise data would be expected to weaken the observed associations and in general underestimate associations.…”

Positive predictive values for self-reported fractures in an adult Japanese population

“…It should be noted that self-reported vertebral fractures are likely to be symptomatic; thus, the results of our study cannot be applied to asymptomatic vertebral fractures. Although a number of studies have shown the selfreporting of limb fractures to be accurate [4][5][6][7], we were unable to demonstrate accurate reporting of upper limb or hip fractures, even for those occurring in the last 5 years. We further investigated nine false positive cases of upper limb fracture reported in the last 5 years and found that five were due to high-energy trauma, one was a fracture at a different anatomical site (the clavicle), one involved fractures predating the study period, and two cases did not involve fractures.…”

“…Several validation studies have confirmed self-reported non-vertebral fractures in Caucasian populations [4][5][6][7]; however, very few studies have addressed the accuracy of selfreported vertebral fractures. One reason may be that vertebral fractures are not common in such populations.…”

High prevalence of vertebral fractures despite normal bone mineral density in patients with long-term controlled acromegaly

“…The prevalence of VFs in acromegalic patients largely exceeded the prevalence in the control population, in all age groups (25). In addition, large European population-based cohort studies also report a much lower prevalence of VFs in both men and women (28)(29)(30)(31)(32), comparable to the findings in the Dutch reference cohort. Our findings, based on the scoring of two independent scorers and confirmed by an experienced radiologist, demonstrate that the prevalence of VFs in acromegalic women, but even more so in acromegalic men, exceeds the reported prevalence of VFs in the general population, including the Dutch population.…”