Table 2 Estimated risk of obsessive-compulsive disorder (OCD) in relatives of individuals with OCD, stratified by tic disorder status
From: A population-based family clustering study of tic-related obsessive-compulsive disorder
Relative sub-cohort | Frequencies (%) | Hazard ratios (95% CI)a | ||||
|---|---|---|---|---|---|---|
Tic-related OCD n = 1257 | Non-tic-related OCD n = 20,975 | Unaffected population n = 4,063,135 | Risk of OCD in relatives of tic-related OCD, compared with OCD unaffected relatives | Risk of OCD in relatives of non-tic-related OCD, compared with OCD unaffected relatives | Risk of OCD in relatives of tic-related OCD, compared with relatives of non-tic-related OCD | |
Twins | 32 (2.55) | 375 (1.79) | 74,717 (1.84) | 25.19 (9.20–68.98) | 13.93 (8.78–22.09) | 2.52 (0.91–7.02) |
Full siblings | 913 (72.63) | 15,608 (74.41) | 3,056,839 (75.23) | 10.63 (7.92–14.27) | 4.52 (4.06–5.02) | 2.11 (1.55–2.87) |
Maternal half siblings | 257 (20.45) | 3783 (18.04) | 560,953 (13.81) | 3.72 (1.92–7.20) | 1.87 (1.39–2.52) | 2.15 (1.12–4.11) |
Paternal half siblings | 273 (21.72) | 3897 (18.58) | 608,861 (14.99) | 0.30 (0.04–2.12) | 1.80 (1.31–2.49) | 0.20 (0.03–1.41) |
Cousins | 874 (69.53) | 14,455 (68.92) | 2,693,527 (66.29) | 1.58 (1.17–2.13) | 1.43 (1.29–1.59) | 1.05 (0.77–1.42) |
