To account for familial effects, we compared patients with OCD and their unaffected siblings (n = 14 834) with regard to all-cause mortality (MRR, 1.87 [95% CI, 1.07–3.27]), natural causes (MRR, 1.91 [95% CI, 1.08–3.36]), and unnatural causes of death (MRR, 3.81 [95% CI, 1.13–12.78]). We found no evidence of familial confounding for causes of death (because the risk estimates were significant and of the same magnitude as those for the controls from the general population) (Table 3).
