Table 3 Estimated risk of obsessive-compulsive disorder (OCD) in relatives of individuals with OCD, stratified by tic disorder status matched (1:5) by age at first diagnosis of OCD
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 = 6,275 | 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) | 145 (0.69) | 74,717 (1.84) | 24.83 (9.05–68.12) | 11.81 (5.58–25.01) | 2.15 (0.86–5.35) |
Full siblings | 913 (72.63) | 4748 (22.64) | 3,056,839 (75.23) | 10.64 (7.93–14.28) | 5.06 (4.31–5.95) | 2.02 (1.44–2.83) |
Maternal half siblings | 257 (20.45) | 1125 (5.36) | 560,953 (13.81) | 3.72 (1.92–7.19) | 2.34 (1.53–3.56) | 1.53 (0.77–3.03) |
Paternal half siblings | 273 (21.72) | 1172 (5.59) | 608,861 (14.99) | 0.30 (0.04–2.12) | 1.48 (0.89–2.46) | 0.20 (0.03–1.45) |
Cousins | 874 (69.53) | 4450 (21.22) | 2,693,527 (66.29) | 1.58 (1.17–2.13) | 1.46 (1.24–1.70) | 1.08 (0.78–1.48) |
