Longitudinal comparison of three depression measures in adult cancer patients

Context: Although a number of depression measures have been used with cancer patients, longitudinal comparisons of several measures in the same patient population have been infrequently reported.

Objectives: To compare the Hopkins Symptom Checklist 20-item depression scale, Short-Form 36 Mental Health Inventory five-item distress scale, and Patient Health Questionnaire nine-item depression scale in adults with cancer.

Methods: Of the 309 cancer patients enrolled in a telecare management trial for depression, 247 completed the three depression measures at both baseline and at three months and a retrospective assessment of global rating of change in depression at three months. Internal consistency and construct validity of each measure were evaluated. Responsiveness was compared by calculating standardized response means and receiver operating characteristic area under the curve, using global rating of change as the external comparator measure. Differences between intervention and control groups in depression change scores were compared by calculating standardized effect sizes (SESs).

Results: Internal reliability coefficients for the three measures were ≥0.77 at baseline and ≥0.84 at three months. Construct validity was supported with strong correlations of the depression measures among themselves, moderately strong correlations with other measures of mental health, and moderate correlations with vitality and disability. In terms of responsiveness, standardized response means for all measures significantly differentiated between three groups (improved, unchanged, and worse) as classified by patient-reported global rating of change in depression at three months. The three measures were able to detect a modest treatment effect in the intervention group compared with the control group (SES ranging from 0.21 to 0.43) in the full sample, whereas detecting a greater treatment effect in depressed participants with comorbid pain (SES ranging from 0.30 to 0.58). Finally, the three measures performed similarly in detecting patients with improvement.

Conclusion: The Hopkins Symptom Checklist 20-item depression scale, Mental Health Inventory five-item distress scale, and Patient Health Questionnaire nine-item depression scale were established as reliable, valid, and responsive depression measures in adults with cancer. Given the current recommendations for measurement-based care, our study shows that clinicians treating depressed cancer patients have several measures from which to choose.