OBJECTIVES: Depression-free days (DFD) and quality-adjusted days (QAD) are used to assess the overall effectiveness of antidepressants for patients with major depressive disorder (MDD). Both metrics estimate utility based on fractions from scores on the Hamilton Rating Scale for Depression (HAM-D). The objective of this study was to develop a new patient-preference weighted metric. METHODS: Data were pooled from two identical ten-week, multicenter, randomized, double-blind, placebo-controlled studies of flexible-dose venlafaxine XR (37.5-300mg/day; mean daily doses in the individual studies were 132mg and 130mg) and sertraline (50-200mg/day; mean daily doses in the individual studies were 89mg and 88mg) in the treatment of DSM-IV MDD (1352 ITT patients). Three health states were defined using HAM-D17 scores: remission = HAM-D£7; response = HAM-D between eight and 15; no response = HAM-D>15. The extended individual model of Quality-Adjusted Time Without Symptoms and Toxicity (Q-TWiST) method was applied to develop quality-adjusted remission days (QUARE), which evaluates treatment trade-offs by incorporating the duration and patient preference (ie, utility) associated with each health state. Effectiveness was measured by the treatment difference on average QUARE days using an ANOVA model with center as a covariate. Threshold utility analysis was applied to address the utility uncertainty as a sensitivity analysis. RESULTS: Over the ten-week acute treatment period, venlafaxine XR was associated with significantly more QUARE days than placebo at all possible utility scenarios (P<0.05). Sertraline was also associated with significantly more QUARE days than placebo at majority of possible utility scenarios. CONCLUSIONS: QUARE is a utility-based measure that could be used as QALY (Quality Adjusted Life Years) directly in cost-effectiveness studies. Different definitions of health states can be applied to derive QUARE in MDD. Venlafaxine XR and sertraline were associated with significantly more QUARE days than placebo in ten-week acute treatment of MDD.