Suicidal ideation. The clinical utility of the K10

Suicidal ideation is an important risk factor for suicide attempts and completions, and early identification of the likely presence of self-harm cognitions would benefit clients and clinicians alike. This study examined the clinical utility of the Kessler K10 psychological distress score as an indicator of suicidal ideation.

Suicidal ideation was assessed on the basis of four relevant questions contained in the General Health Questionnaire (GHQ-28), and these were subsequently analyzed against the K10 scores. The data were collected using a monthly risk-factor surveillance system where each month a representative random sample of South Australians over the age of 16 years is interviewed. The cumulative data covered the period 2002 to 2007 (n = 12,884).

Psychological distress and suicidal ideation were reported by 9.9% and 5.1% of the participants, respectively. Univariate analysis demonstrated a positive linear relationship between the K10 score and suicidal ideation. Participants scoring in the very high range of the K10 were more likely to report suicidal ideation and this was experienced with greater frequency than by those who were less distressed. A logistic regression analysis revealed that even those in the moderate category were four times more likely to experience suicidal ideation than those in the low category, and those in the high and very high categories were 21 and 77 times more likely, respectively. Separate models based on sex and using odds-ratios based on very high vs. low K10 scores showed that males were 104 times more likely to report suicidal ideation compared to a 63 times higher rate for females. Both sexes had a 52% probability of experiencing suicidal ideation if they fell into the very high distress group.

The K10 score is a clinically useful indicator of the presence of suicidal ideation.