Objective: To develop and validate a multidimensional generic questionnaire measuring satisfaction with treatment with medicines. The questionnaire was designed to be used in chronic patients undergoing pharmacological treatment for any disease.
Methods: After a literature review and cognitive debriefing process with an expert panel of six members and 21 chronic patients in four focus groups, a preliminary instrument with 36 items grouped into six dimensions was developed. Three samples of patients were enrolled during the whole process: 1) 12 patients to assess feasibility and pertinence of items; 2) 150 patients for item reduction; and 3) 455 patients for psychometric properties assessment of the instrument. The latter two were stratified by gender, age, and main disease (type 2 diabetes, hypertension, osteoarthritis, benign prostate hyperplasia, chronic obstructive pulmonary disease/asthma, depression, and migraine). Additional measures were gathered for concept validity: clinical and treatment information, patient and clinician assessment of treatment tolerability and effectiveness, treatment satisfaction (Treatment Satisfaction Questionnaire for Medication [TSQM]), and therapeutic compliance (Morisky-Green). Feasibility, reliability, and validity (content, discriminant, construct, and concurrent) were assessed.
Results: Factor analysis item reduction resulted in a 17-item questionnaire with six dimensions: treatment effectiveness, convenience of use, impact on daily activities, medical care, global satisfaction, and undesirable side effects. Unidimensional scales (Cronbach's alpha ranging 0.813-0.912) were correlated, and allowed computation of a summary composite score (alpha = 0.890). SATMED-Q dimensions showed moderate but significant correlations with TSQM dimensions (0.577-0.680). Differences between tolerability and effectiveness groups were found, depending on dimension and whether the clinician or the patient were informing. Therapeutic compliance groups showed differences in some treatment satisfaction dimensions.
Conclusions: The SATMED-Q is a reliable and valid measure of treatment satisfaction, structured in six dimensions, and a summary composite score. Additional work is needed to assess sensitivity to change.