Self-reporting provides useful information for assessing the risk factors of osteoporotic fractures in large cohort studies. However, to data, no studies in Japan have confirmed the accuracy of this approach in this context. The aim of the study reported here was to determine the positive predictive value (PPV) for the self-reporting of fractures.

A total of 133 participants of the Oguni cohort in the Japan Public Health Center-based Prospective Study who reported a vertebral, upper limb, or hip fracture on the 15-year follow-up questionnaire survey were evaluated. The accuracy of fractures was confirmed by cross-referencing medical records.

The average age of the participants was 72.4 (standard deviation 7.9) years. The PPV for vertebral fracture in the last 15 years was 17/20 (85.0%) for women and 2/9 (22.2%) for men, for a total of 19/29 (65.5%). PPVs for upper limb and hip fractures were as low as 30/68 (44.1%) and 12/22 (54.5%), respectively.

Female self-reporting provided PPVs suitable for symptomatic vertebral fracture over 15 years and can be used as an outcome measure in large cohort studies in Japan.