Implications of two-stage depression screening for identifying persons with thoughts of self-harm

Persons with thoughts of self-harm may need evaluation for suicide risk. We examine the prevalence of thoughts of self-harm and whether persons with thoughts of self-harm are identified when two-stage depression screening is used.

Data are from the 2005-2010 National Health and Nutrition Examination Surveys. Persons responding positively to question nine of the Patient Health Questionnaire-9 (PHQ-9) are identified as having thoughts of self-harm. We compare two depression cutoff scores for the Patient Health Questionnaire-2 (PHQ-2) to see what percentage of persons with thoughts of self-harm would be identified as needing further screening with the PHQ-9.

The prevalence of thoughts of self-harm was 3.5%. Persons 12-17 years old, poor and reporting fair or poor health were more likely to report thoughts of self-harm. A cutoff score of three on the PHQ-2 identified 49% of persons with thoughts of self-harm for further screening with the PHQ-9. A cut point of two increased the proportion of persons with thoughts of self-harm continuing for further screening to 76%.

Using a lower cutoff score, two, the PHQ-2 captures more persons with thoughts of self-harm. One quarter of persons with self-harm thoughts may not be identified for further screening when two-stage screening is used.