Figure 3
Kaplan Meier survival analysis of relapse over 24 weeks. Time to relapse (Cox model, with treatment and age group as covariates) showed significant advantage for treatment with escitalopram compared to placebo, with an estimated hazard ratio of 4.4 (chi-square test, df = 1, χ2 = 22.5, p < 0.001), whereas the effect of age group was not significant, with an estimated hazard ratio of 1.2 for old-old versus young-old (chi-square test, χ2 = 0.41, df = 1, p = 0.520).