Background: We have no questionnaires to assess satisfaction with antidepressant treatment, which affects the health related quality of life. The objective was to develop and validate a specific instrument to assess satisfaction with antidepressant treatment, determining convergent validity regarding clinical effectiveness, fulfillment of expectations, adherence and tolerability.
Methods: Longitudinal observational study where 168 patients started antidepressant treatment and were followed for one year. The variables included adverse effects, compliance and intensity of depressive symptoms. The questionnaire for the Evaluation of Antidepressant Treatment Satisfaction (ESTA) consists of 11 items answered using Likert scale. We evaluated its reliability, construct validity and concurrent validity with conceptually related measures with the construct assessed.
Results: The Cronbach's alpha statistic ranged between 0.936 and 0.951. In the factor analysis one factor accounted for 64.11% of the variance. The average score of the questionnaire ranged from 40.0 to 44.7 points, showing a negative correlation regarding the Hamilton scale (-0.321 / -0.601) and Montgomery-Asberg scale (-0.491 / -0.307). After a month, the antidepressant treatment satisfaction was 39.5 points in noncompliant patients and 44.3 in compliers. In those who had adverse effects was 39.2 versus 43.3 for those who had not. At the first visit (15 days) the score was 40.0, in a month 42.6, in 3 months 44.4 and in 6 months 44.5. These differences were statistically significant (p <0.05). In test-retest analysis, intraclass correlation coefficient was 0.908.
Conclusions: The questionnaire, designed to assess satisfaction with antidepressant treatment, is valid and reliable, and provides a patient-centered instrument which is complementary to the clinical assessment of the effectiveness of antidepressant treatment.