Measuring depression in prostate cancer patients: does the scale used make a difference?

Area of Science:

• Oncology
• Psychiatry
• Psychometrics

Background:

• Prostate cancer (PCa) patients experience significant psychological distress, including depression.
• Accurate assessment of depression is crucial for effective management in PCa patients.
• Multiple self-report depression scales exist, but their comparability in PCa populations is unclear.

Purpose of the Study:

• To investigate differences in depression scores and severity classification using three standardized scales in prostate cancer patients.
• To compare the performance of the Hospital Anxiety and Depression Scale Depression subscale (HADS-D), Self-rating Depression Scale (SDS), and Patient Health Questionnaire (PHQ-9).

Main Methods:

• A sample of 138 prostate cancer patients in Queensland, Australia, completed mail-out self-report questionnaires in May 2014.
• Data were collected using the HADS-D, SDS, and PHQ-9 for depression assessment.
• Statistical analyses were performed to compare scale scores, severity classifications, and subsyndromal depression criteria.

Main Results:

• Significant correlations were found between total scores from the three depression scales.
• However, severity classifications differed substantially across scales, with HADS-D and SDS showing considerable underestimation compared to PHQ-9.
• When assessing subsyndromal depression, statistically significant differences emerged, indicating underestimation by HADS-D and SDS relative to PHQ-9.

Conclusions:

• The choice of depression scale significantly impacts the estimation of depression severity and prevalence in prostate cancer patients.
• Differences in scale construction and included items can lead to underestimation of depression by HADS-D and SDS compared to PHQ-9.
• Findings have implications for research comparability and clinical practice in managing depression among PCa survivors.