Comparison of the SF-36 Five-item Mental Health Inventory and Beck Depression Inventory for the screening of depressive symptoms in chronic dialysis patients

BACKGROUND: The Beck Depression Inventory (BDI) is a standard and validated questionnaire to screen for depressive symptoms in chronic dialysis patients, but is relatively extensive to use repeatedly in clinical practice. We investigated whether the five-item Mental Health Inventory (MHI-5) of the 36-item Short-Form Health Survey Questionnaire (SF-36) could be applied to screen for depressive symptoms in dialysis patients. Moreover, we determined the optimal MHI-5 cut-off score to assess depressive symptoms. METHODS: Chronic dialysis patients from three centres filled out the SF-36 and the BDI. A receiver operating characteristic (ROC) curve was constructed for the MHI-5 score with BDI ≥ 16 as reference standard to (i) calculate the area under the curve to determine whether the MHI-5 could be considered as a useful screening instrument for depressive symptoms and (ii) proxy the optimal cut-off score of the MHI-5 to assess depressive symptoms. The optimal cut-off score was determined by the value for which the sum of sensitivity and specificity had an optimum. RESULTS: Of 133 included patients, 23% had depressive symptoms as determined with BDI ≥ 16. The correlation of the BDI with MHI-5 was -0.64. The area under the ROC curve was 0.82 (95% confidence interval 0.74-0.90). The optimal cut-off point of the MHI-5 was 70. MHI-5 ≤ 70 had 77 sensitivity, 72 specificity, 44 positive predicting value and 91% negative predicting value with the presence of depressive symptoms determined with BDI ≥ 16. CONCLUSIONS: The MHI-5 may help clinicians to screen for depressive symptoms in dialysis patients without using an additional depression screening questionnaire once the SF-36 is completed. A cut-off value of 70 can be used safely for the purposes of screening applications.