Background: Several studies have attempted to predict the final response or remission based on improvement during the early course of treatment of major depression. There is however a great variation in cut offs used to define early response and in the optimal week to predict final results.
Objective: To compare different cut offs at different time points early in the treatment of elderly depressed patients.
Method: A 12 week randomised, controlled trial in 81 elderly inpatients with DSM-IV major depression comparing venlafaxine with nortriptyline. At least 20, 25, 30 or 50% improvement was analysed after 1, 3 and 5 weeks using the Hamilton Depression Rating Scale and the Montgomery Asberg Depression Rating Scale. We plotted sensitivity against 1-specificity and calculated areas under the curve (AUCs).
Results: The highest percentage of correctly classified patients is found using at least 50% decrease as cut off in week 5, with acceptable sensitivity (81.8%) and specificity (87.4%). In week 5, the AUCs were 0.891 (95% CI 0.798-0.984) and 0.866 (95% CI 0.789-0.983) for the HAM-D and MADRS, respectively.
Conclusions: Combining the results from our study and the other studies addressing this issue, we suggest that the treatment should be changed in the elderly if after 3-4 weeks less than 30% improvement in depression score has been achieved.
Copyright 2009 John Wiley & Sons, Ltd.