Suicide following a conviction, solitary confinement, or transfer in people incarcerated: A comprehensive retrospective cohort study in France, 2017-2020

Introduction: Suicide rates are higher in prison than in the general population in most countries. The proximity of some suicides to prison events has only received little attention in comparative studies. The aim of this study was to assess the relationship between suicide and four prison events: conviction, disciplinary solitary confinement, nondisciplinary solitary confinement and inter-prison transfer, in a national retrospective cohort study of people in prison.

Methods: All incarcerations in France that occurred during 2017-2020 were eligible. Data were collected from an administrative database of the National Prison Service. Survival bivariate and multivariate analyses were performed with a Cox regression model.

Results: Of 358,522 incarcerations were included, among which 469,348 events and 449 suicides occurred. In multivariate analysis, suicide risk was higher the first day of disciplinary solitary confinement (HR = 42.1 [21.5-82.7] and HR = 119.0 [71.5-197.9], before and after a government decree on the disciplinary system, respectively. It was higher within 2 weeks after a transfer (HR = 3.5 [2.3-5.2])) or entry in nondisciplinary solitary confinement (HR = 6.7 [3.4-13.3]) and lower within 2 weeks after a conviction (HR = 0.6 [0.4-1.0]).

Conclusion: Solitary confinement and transfer were found to be precipitating factors of suicide in people who are incarcerated. These results offer interesting perspectives on prevention.