Our collaboration with MHRN health systems to improve depression care has emphasized the systematic use of standard outcome measures – like the PHQ9 depression scale. More recently, we have encouraged use of the 9th item of the PHQ9 (regarding thoughts of death or self-harm) as a tool for identifying people at risk for suicidal behavior. Front-line clinicians and health system managers often ask whether those standard questionnaires can accurately measure depression or predict suicidal behavior across diverse patient populations.
Those questions about questionnaires are typically prompted by concern about wording of specific questionnaire items. For example: Does a question about “feeling tired or having little energy” really assess depression in people with diabetes or heart disease? Does a question about “thoughts you would be better off dead” really assess risk of suicidal behavior in older adults with chronic medical illness?
A recent MHRN paper led by Rebecca Rossom directly addresses that second question – using a sample of almost 1 million PHQ9 questionnaires completed by almost 300,000 patients in four health systems. Her team found that response to item 9 of the PHQ9 was a strong predictor of subsequent suicide attempt and suicide death across all age groups, including those aged 65 or older. Among those reporting frequent “thoughts you would be better off dead or thoughts of hurting yourself in some way”, risk of suicide death over the following two years was actually highest in those aged 65 or older.
Those data would seem to settle the question. Reporting “thoughts you would be better off dead” should not be dismissed as a normal part of aging or a normal reaction to chronic illness. The burdens of chronic illness might certainly contribute to depression and suicidal ideation. Empathy regarding those burdens is certainly an appropriate response, but a false sense of security is not.
This analysis is also a nice example of using data to escape from semantic arguments that abound in Alice’s Wonderland. As we move forward with systematic assessment of outcomes in mental health care, we will likely encounter more questions about what a particular word or questionnaire item means. Rather than responding like Humpty Dumpty, we can ask in return “What data would we need to figure that out?”