Effects of depression and antidepressant medications on hip fracture

This study was conducted to investigate the effects of depression and antidepressant medications on hip fracture. The database of the Taiwan National Health Insurance with medical records of more than 1,000,000 individuals was searched for patients who had hip fracture with or without depression from 1998 to 2009. Patients with the following conditions were excluded: hip fracture due to cancer or traffic accidents, hip fracture that occurred before the diagnosis of depression, and use of antidepressants before the diagnosis of depression. A matched cohort of 139,110 patients was investigated, including 27,822 (17,309 females; 10,513 males) with depression and 111,288 (69,236 females; 42,052 males) without depression (1:4 randomly matched with age, sex, and index date). Among these patients, 232 (158 females and 74 males) had both hip fracture and depression, and 690 (473 females and 217 males) had hip fracture only. The Cox proportional-hazards regression method was used to determine the effect of depression on hip fracture. The hazard ratio (HR) for each clinical parameter was calculated after adjusting for confounders including sex, age, Charlson comorbidity index, urbanization, osteoporosis, and antidepressants. Results showed that patients with major depressive disorder had a 61% higher incidence of hip fracture than those without depression (HR 1.61, 95% confidence interval [CI] 1.19-2.18, P = 0.002). The risk of hip fracture for patients with less severe depressive disorder (dysthymia or depressive disorder, not otherwise specified) was not statistically higher than that of patients with no depression (HR 1.10, 95% CI = 0.91-1.34, P = 0.327). Among the patients with depression, females had a 49% higher incidence for hip fracture than males (HR 1.49, 95% CI 1.30-1.72, P < 0.001). The incidence of hip fracture also increased with age and Charlson comorbidity index scores. Analyses of both all (139,110) patients and only patients (27,822) with depression revealed that antidepressants had no negative impact on the incidence of hip fracture. In conclusion, major depression was found to be a risk factor for hip fracture and that use of antidepressants had no adverse effect on hip fracture in the Taiwanese population.