A risk-scoring scheme for suicide attempts among patients with bipolar disorder in a Thai patient cohort

BACKGROUND In Thailand, risk factors associated with suicide attempts in bipolar disorder (BD) are rarely investigated, nor has a specific risk-scoring scheme to assist in the identification of BD patients at risk for attempting suicide been proposed. OBJECTIVE To develop a simple risk-scoring scheme to identify patients with BD who may be at risk for attempting suicide. METHODS Medical files of 489 patients diagnosed with BD at Suanprung Psychiatric Hospital between October 2006 and May 2009 were reviewed. Cases included BD patients hospitalized due to attempted suicide (n = 58), and seven controls were selected (per suicide case) among BD in- and out-patients who did not attempt suicide, with patients being visited the same day or within 1 week of case study (n = 431). Broad sociodemographic and clinical factors were gathered and analyzed using multivariate logistic regression, to obtain a set of risk factors. Scores for each indicator were weighted, assigned, and summed to create a total risk score, which was divided into low, moderate, and high-risk suicide attempt groups. RESULTS Six statistically significant indicators associated with suicide attempts were included in the risk-scoring scheme: depression, psychotic symptom(s), number of previous suicide attempts, stressful life event(s), medication adherence, and BD treatment years. A total risk score (possible range -1.5 to 11.5) explained an 88.6% probability of suicide attempts based on the receiver operating characteristic (ROC) analysis. Likelihood ratios of suicide attempts with low risk scores (below 2.5), moderate risk scores (2.5-8.0), and high risk scores (above 8.0) were 0.11 (95% CI 0.04-0.32), 1.72 (95% CI 1.41-2.10), and 19.0 (95% CI 6.17-58.16), respectively. CONCLUSION The proposed risk-scoring scheme is BD-specific, comprising six key indicators for simple, routine assessment and classification of patients to three risk groups. Further validation is required before adopting this scheme in other clinical settings.