Tricyclic antidepressant use and risk of fractures: A meta-analysis of cohort and case-control studies

Because studies of the association between tricyclic antidepressant (TCA) treatment and risk of fracture have shown inconsistent findings, we sought to assess whether people who take TCAs are at increased risk of fracture. Relevant studies published by June 2012 were identified through database searches of Scopus, MEDLINE, EMBASE, PsycINFO, ISI Web of Science, and WorldCat Dissertations and Theses from their inception, and manual searching of reference lists. Only original studies that examined the association between TCA treatment and risk of fracture were included. Two investigators independently conducted literature searches, study selection, study appraisal, and data abstraction using a standardized protocol. Disagreements were resolved by consensus. Twelve studies met inclusion criteria. Because of the heterogeneity of these studies, random-effects models were used to pool estimates of effect. Overall, TCA use was associated with significantly increased fracture risk (relative risk [RR], 1.45; 95% confidence interval [CI], 1.31-1.60; p < 0.001). Increased fracture risk associated with TCA use was also observed in studies that adjusted for bone mineral density (RR, 1.54; 95% CI, 1.24-1.90; p < 0.001) or depression (RR, 1.49; 95% CI, 1.28-1.67; p < 0.001). Strength of association with TCA exposure duration ≥6 weeks (RR, 1.13; 95% CI, 1.00-1.28) was substantially weaker than association with TCA exposure duration <6 weeks (RR, 2.40; 95% CI, 1.41-4.08). Prior TCA exposure had no significant effect on fracture risk (RR, 1.04; 95% CI, 0.86-1.26; p = 0.70). After accounting for publication bias, we found the overall association between TCA use and fracture risk to be slightly weaker (RR, 1.36; 95% CI, 1.24-1.50) but still significant (p < 0.001). Findings of this meta-analysis indicate that treatment with TCAs may convey an increased risk of fracture, independent of depression and bone mineral density.