A Study on the Correlation Between Subjective and Objective Scales in the Evaluation of Depressive Symptoms for the Elderly

Objective: The aim of this study was to investigate the correlation between subjective and objective depression rating scale for the elderly with depressive symptoms. Methods: Thirty three outpatients aged more than 55 with depressive symptoms were assessed with the Patient Health Questionnare-9 (PHQ-9) and the Montgomery-Asberg Depression Rating Scale (MADRS). Similar items from each scale were paired to investigate their correlations. The level of agreement between the PHQ-9 and the MADRS was also assessed for subjects by using discrepancy-score. Results: Correlation between total scores of the PHQ-9 and the MADRS was significant (r=0.85, p<0.001). There were significant correlations between the paired items except for the item about volition. These results were the same in the group whose total education years are 7 or more. However, in the group whose total education years are 6 or less, there was no significant correlation between the paired items about sleep, concentration and volition. Conclusion: These results demonstrate that using the PHQ-9 in elderly patients is reliable and education level might be considered when interpreting the scale.