Trajectories of service contact before suicide in people with substance use disorders: A national register study

Objective: This study aimed to identify trajectories of service use during the last year before suicide death and the characteristics associated with the trajectories in patients with substance use disorders. Methods: This study used a national registry data linkage, which included all patients with substance use disorders who died by suicide in Norway between 2010 and 2018. In- and outpatient contacts with mental health or substance use services during the last year before suicide death was analyzed by week using Sequence State Analysis and cluster analysis to identify trajectories. Logistic regression was used to measure the association between the characteristics and the trajectories. Results: We identified four trajectories of service contact. A brief contact trajectory (n = 366) with a low proportion of weeks in contact (M weeks = 8.3), associated with less psychosis or bipolar disorder (aOR = 0.13 (0.08-0.22)) and higher age. A regular contact trajectory (n = 160), with a higher proportion of contact (M weeks = 47.9), associated with psychosis or bipolar disorder (aOR = 3.66 (2.10-6.47)) and depressive or anxiety disorder (aOR = 3.11 (1.93-5.13)). An intermittent contact trajectory (n = 195) with most contacts with outpatient substance use disorder services (M weeks = 9.7). A continuous contact trajectory (n = 109) with a high proportion of inpatient contact (M weeks = 44.5), strongly associated with psychosis or bipolar disorder (aOR = 6.08 (3.26-11.80)). Conclusion: Longitudinal descriptions of service use reveal different trajectories that are important to consider when developing policies or interventions to reduce the risk of suicide death in patients with substance use disorders.