The risk of a second hip fracture in patients after their first hip fracture.

We investigated the incidence of additional fractures and the rate of prescription of osteoporotic pharmacotherapy after an initial hip fracture. We surveyed female patients aged 65 and over who sustained their first hip fracture between January 1, 2006, and December 31, 2007, treated at 25 hospitals in five geographic areas in Japan. Data for 1 year after the first hip fracture were collected from medical records, and questionnaires were mailed to all patients. In total, 2,663 patients were enrolled, and 335 patients were excluded based on exclusion criteria. The analysis was performed on 2,328 patients. During the 1-year follow-up period 160 fractures occurred in 153 patients and 77 subsequent hip fractures occurred in 77 patients. The incidence of all additional fractures among patients who sustained their first hip fracture was 70 (per 1,000 person-year) and that for second hip fracture was 34. In comparison to the general population, women ≥65 years of age who sustained an initial hip fracture were four times as likely to sustain an additional hip fracture. Antiosteoporosis pharmacotherapy was prescribed for 436 patients (18.7%), while 1,240 patients (53.3%) did not receive any treatment during the 1-year period. Patients who have sustained one hip fracture have a higher risk of a second hip fracture compared to the general population, and most of these women receive no pharmaceutical treatment for osteoporosis.