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.