30-year trends of hip and vertebral fracture incidence in Japan: a systematic review and meta-analysis

Introduction A previous review study showed the trends of declining age- and sex-adjusted incidence of hip fractures in almost all the countries, except Austria and Japan, in the most recent of the periods studied. However, the expansion of devices for diagnosis and drugs for fracture prevention in Japan was roughly the same as in the other countries. This study aimed to conduct a comprehensive systematic review and meta-analyses of incidence rates (IRs) of osteoporotic fractures reported over 30-years in multiple communities in Japan and to evaluate secular trends. Materials and Methods We searched MEDLINE for observational studies reporting IRs of osteoporotic fractures in the general population. Additional studies were identified by hand searches of reference lists of published studies. Two reviewers and 1 expert independently assessed study eligibility. Pooled analyses of IRs were conducted by a random-effect model. Data from 3 periods (1985–1999, 2000–2009, and from 2010) were compared. Results Of 47 eligible studies, 21 with IRs or information enabling recalculation of IRs in the population aged 50 years and older were included. IRs of hip fractures per 100,000 person-years significantly increased over time in men: 1985–1999, 0.79 (95% CI 0.71–0.87); 2000–2009, 1.18 (95% CI 1.09–1.28); and 2010 onwards, 1.31 (95% CI 1.17–1.45). They also significantly increased in women: 2.23 (95% CI 1.89–2.58); 3.99 (95% CI 3.70–4.28); and 4.39 (95% CI 4.00–4.78), respectively. Conclusion IRs of hip fractures continuously increased in the past 30-years in men and women despite improved the diagnosis, treatment, and care. Such data from Japan, a leading aging society, provide important information for other countries.