Analysis of HAM-D scores and working ability in an observational study of Japanese patients with major depressive disorder and painful physical symptoms treated with duloxetine or SSRI monotherapy

OBJECTIVE: To investigate the relationship between Hamilton Depression Rating Scale (HAM-D) score and psychiatrists’ judgment of working ability in patients with major depressive disorder (MDD) and painful physical symptoms. METHODS: This was a prospective, observational, 12-week study in patients who received duloxetine or a selective serotonin reuptake inhibitor. Patients were ≥20 years old, resided in Japan, and had at least moderate depression (Quick Inventory of Depressive Symptomatology ≥16) and at least moderate painful physical symptoms (Brief Pain Inventory-Short Form average pain ≥3). The main outcome in this post-hoc analysis was the HAM-D17 cutoff best corresponding with patients’ working ability according to the investigator’s judgment. Area under the receiver-operator curve was used to determine the time point with the strongest relationship between HAM-D17 and working ability. The optimal HAM-D17 cutoff was determined based on the maximum of sensitivity (true positive rate) minus ([1 minus specificity] [true negative rate]). For the evaluation of binary data, a mixed effects model with repeated measures analysis was used. RESULTS: For the estimation of the HAM-D17 cutoff, the area under the receiver-operator curve was maximal at 12 weeks, when a HAM-D17 score of 6 resulted in the best correspondence with working ability in the combined study population. At 12 weeks, a HAM-D17 score of 6 also resulted in the maximum predictive ability in each of the two treatment groups separately. For predicted working ability at 12 weeks, 52.7% of duloxetine-treated patients achieved the HAM-D17 cutoff of ≤6, whereas 48.5% of SSRIs-treated patients achieved HAM-D17 ≤6 (P=0.477). CONCLUSION: In this study of patients with major depressive disorder and painful physical symptoms, a HAM-D17 score ≤6 corresponded best with patients’ working ability. This finding is consistent with previous studies showing that a HAM-D17 cutoff of ≤7 may overestimate functional recovery from MDD.