In Reply: In response to Dr Bollu and colleagues, the duration of use of finasteride was highly correlated with total dose. The median (25th-75th percentile) time from first prescription to fracture/index date was 1.6 years (0.8-3.7 years) for case patients and 2.1 years (0.9-3.8 years) for control patients. When stratified by time since first prescription for finasteride (overall median), the inverse relationship with hip fracture was fairly consistent across categories of cumulative dose among men with more remote first prescriptions (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.31-1.19; OR, 0.69; 95% CI, 0.37-1.26; and OR, 0.54; 95% CI, 0.25-1.15 for men with cumulative doses of 10-500 mg, 501-2750 mg, and ≥2751 mg, respectively). For men with more recent first prescriptions, the relationship was attenuated with larger cumulative doses (OR, 0.68; 95% CI, 0.38-1.22; OR, 1.17; 95% CI, 0.69-1.99; and OR, 1.66; 95% CI, 0.32-10.69 for men with cumulative doses of 10-500 mg, 501-2750 mg, and ≥2751 mg, respectively), but the estimates were unstable due to the small numbers of men with both large doses and recent prescriptions.
Jacobsen SJ, Shi JM, Loo RK. 5-α Reductase Inhibitors and Risk of Hip Fracture—Reply. JAMA. 2009;301(9):935. doi:10.1001/jama.2009.183