Effect of assertive case management intervention on suicide attempters with comorbid Axis I and II psychiatric diagnoses: secondary analysis of a randomised controlled trial

Background Most suicide attempters suffer from psychiatric disorders, which are often comorbid with personality disorders. The effects of intervention on patients who have attempted suicide with comorbid Axis I and II diagnoses have not been fully elucidated. We evaluated whether assertive case management can reduce the repetition of suicidal behaviours in patients who had attempted suicide with comorbid Axis I and II diagnoses. Methods This study was a secondary analysis of a randomised controlled trial investigating whether assertive case management could reduce the repetition of suicide attempts, compared with enhanced usual care. Subjects were divided into those who had comorbid Axis I and II diagnoses (Axis I + II group), and those who had an Axis I diagnosis without Axis II comorbidity (Axis I group). Outcome measures were compared between patients receiving a case management intervention and patients receiving enhanced usual care, as allocated. The primary outcome measure was the incidence proportion of the first episode of recurrent suicidal behaviour at 6 months after randomisation. We calculated risk ratios (RR) with 95% confidence intervals (CI) at 6 months and 12 months after randomisation of patients in the Axis I and Axis I + II groups. Results Of 914 enrolled patients, 120 (13.1%) were in the Axis I + II group, and 794 (86.9%) were in the Axis I group. Assertive case management was significantly effective for the Axis I group on the primary outcome at 6 months (risk ratio [RR] 0.51, 95% confidence intervals [CI] 0.31 to 0.84). The RR of the Axis I + II group was 0.44 (95% CI 0.14 to 1.40). Conclusions Assertive case management not only had an effect on patients who had attempted suicide with only Axis I disorders but may also have a similar effect on patients with comorbid Axis I and II disorders.