5%) than in counterpart live controls (11.8%; table 4). Hence, the effect of selleck COPD on suicide risk interacted significantly with psychiatric history (test of effect difference: χ2=47.55, p<0.001 after adjustment for sociodemographic variables). Table 4 Effect of hospitalised COPD on risk for subsequent suicide by psychiatric history In general, a hospitalised COPD increased suicide risk significantly more in individuals with no recorded history

of psychiatric illness (OR 2.6, 95% CI 2.3 to 2.9) than it did for individuals with a psychiatric history (OR 1.2, 95% CI 1.0 to 1.5) after having controlled for the main effect of psychiatric illness and the effects of socioeconomic factors. Regardless of sex and age, COPD denoted a significant risk factor for suicide in people without a psychiatric history. For individuals with a prior hospital contact because of psychiatric illness, the additional risk of suicide associated with COPD remained highly significant only in female participants and in patients above 60 years. Discussion Key findings and comparison with the literature In this large population study, we found a significantly increased risk of suicide among patients

previously hospitalised for COPD compared with persons without a history of COPD hospitalisation. The relative risk remained highly significant after adjustment for psychiatric history and sociodemographic variables, and increased progressively with frequency and recency of COPD hospitalisation. In the meantime, suicide risk associated with COPD differed significantly by sex, age and psychiatric status; it was more pronounced in women, in individuals older than 60 years, and in persons with no history of psychiatric illness. These findings confirm previous reports on COPD being related to an elevated risk of suicidal ideation and suicide attempt

or self-harm7 13–15 17 as well as suicide death.7 14 16 They extend the literature demonstrating that the effect of COPD on suicide risk differs significantly by sex, age and psychiatric Brefeldin_A status of the participants, and provide further insights into suicide risk in relation to recency and frequency of COPD hospitalisation for treatment. In their studies, Goodwin et al13 found that physical illness including COPD and lung diseases are related to suicide attempts among adults in the USA.15 The authors also argued for a dose–response relationship between the number of diagnosed physical conditions and the risk of suicide attempt. This notion is supported by our findings of an elevated risk of suicide completion associated with multiple hospitalisations and recency of the last COPD hospitalisation.