Risk of suicide death in psychiatric patients according to the level of continuity of care and area deprivation: A population-based nested case-control study.

Continuity of care and area deprivation have been implicated as possible risk factors of suicide in psychiatric patients. This nested case-control study aimed to examine the association between continuity of care and area deprivation and suicide death in patients with psychiatric disorders. Data were collected from the Korean National Health Insurance Service National Sample Cohort, 2003-2013. The subjects were 974 patients with psychiatric disorders who completed suicides. Each case was compared to three control cases with propensity score matching by gender, age, and follow-up period with incidence density sampling, comprising the final control group of 2,922 living patients. Hazard ratios (HR) for suicide risk considering continuity of care and area deprivation were analysed using a multiple conditional logistic regression. The average follow-up periods between the case and control groups were not statistically different (case: 277.6 weeks, control: 271.4 weeks, p = .245). Both poor continuity of care and higher area deprivation proved to be associated with increased risk of suicide (poor continuity of care; adjusted HR [AHR]: 3.38, 95% confidence intervals [CI]: 2.58-4.43, highest area deprivation; AHR: 1.93, 95% CI: 1.53-2.44). Poor continuity of care combined with highest area deprivation showed a negative synergistic effect on a highly increased risk of suicide (AHR: 2.88, 95% CI: 1.45-5.74). Age was effect modified between suicide risk and poor continuity of care as well as suicide risk and higher area deprivation. A strong patient-provider relationship with good continuity of care may lead to a lower possibility of suicide in psychiatric patients. Moreover, improving community capacity for suicide prevention as well as appropriate postvention should be addressed.