Sex-specific Longitudinal Comparison of CES-D and PHQ-9 Depression Scales. A Concordance Analysis using data from the population-based Heinz Nixdorf Recall Study

Abstract Background To measure depressive symptoms in population-based studies, there are two well-established questionnaires: the Center for Epidemiologic Studies Depression Scale (CES-D) and the Patient Health Questionnaire-9 (PHQ-9). So far, comparisons between both instruments have only been performed using cross-sectional data, and in specific patient groups. Furthermore, comparisons for population-based studies are missing as well as sex-specific analyses. The aim is to evaluate the psychometric properties and concordance of the longitudinal results of CES-D and PHQ-9 in the German population-based Heinz Nixdorf Recall (HNR) study. Methods We used data of n=3,084 participants (48.8% men, mean age: 66.8 years). CES-D and PHQ-9 were assessed in the 8th (t8) and 9th (t9) annual postal follow up within two years via questionnaires. Depressive symptoms were defined as CES-D score ≥ 17 and PHQ-9 score ≥ 10. Internal consistency reliability, convergent validity, and agreement between PHQ-9 and CES-D were assessed using respectively Cronbach’s alpha, Pearson’s correlation, and Cohen’s kappa. To analyse depressive symptoms differences between t8 and t9 we used McNemar’s test. Sex-stratified results are presented. Results The prevalence of depressive symptoms at t8 was higher for CES-D (7.8%) than for PHQ-9 (4.4%). The prevalence slightly increased for CES-D (8.1%), as well as for PHQ-9 to 4.5% at t9. Internal consistency of the PHQ-9 and CES-D was good at both times (Cronbach’s alpha: CES-D t8 & t9: 0.89, PHQ-9 t8: 0.84; t9: 0.85). Cohen’s kappa of agreement between CES-D and PHQ-9 was moderate at both time points (t8: k=0.57; 95% CI: 0.51, 0.63; t9; k=0.58; 95% CI: 0.52, 0.64). For both instruments, the McNemar’s test revealed no differences in the proportion of depressives between t8 and t9. We could not observe sex-specific differences of psychometric characteristics, whereas the agreement between the CES-D and PHQ-9 performed slightly higher in men than in women (t8: k=0.61, resp. k=0.55). Conclusions The results do not support the superiority of one of the scales. Both scales perform well in this population-based cohort in both sexes and longitudinal approach. The decision, which scale to use may depend on characteristics other than the accuracy of the scale, including feasibility and clinical usability.