Background: Tricyclic antidepressants (TCAs) are associated with an increased risk of falls and hip fractures in elderly people. Selective serotonin-reuptake inhibitors (SSRIs) are reported to be better tolerated than TCAs. We investigated the risk of hip fractures associated with SSRIs and TCAs.

Methods: This case-control study used administrative healthcare data from the province of Ontario, Canada. 8239 cases-patients aged 66 years or older, treated in hospital between April, 1994, and March, 1995, for hip fracture-were each matched for age and sex to five controls. Logistic regression was used to calculate the odds ratio for hip fracture with adjustment for potential confounding effects produced by concomitant drug use and comorbidity.

Findings: With participants who had no exposure to antidepressants as the reference category, the adjusted odds ratio for hip fracture was 2.4 (95% CI 2.0-2.7) for exposure to SSRIs, 2.2 (1.8-2.8) for exposure to secondary-amine TCAs, and 1.5 (1.3-1.7) for exposure to tertiary-amine TCAs. For all types of antidepressants, current use was associated with a higher risk of hip fracture than former use. The odds ratios for hip fracture were higher for new current users than for continuous current users in all three drug classes. The proportion of current use in the low-dose range was 22% for SSRIs, 50% for secondary-amine TCAs, and 58% for tertiary-amine TCAs.

Interpretation: Exposure to any of the three classes of antidepressants is associated with a significant increase in the risk of hip fracture. Despite differences in dose distribution, this analysis suggests that SSRIs do not offer an advantage over TCAs in terms of risk of hip fracture.