Validation of the Treatment Satisfaction Questionnaire for Medication in patients with cystic fibrosis

Abstract

Background: Our objective was to confirm the measurement properties of the Treatment Satisfaction Questionnaire with Medication (TQSM) in patients with cystic fibrosis (CF) receiving inhaled antibiotics.

Methods: The TSQM was included in the EAGER study, a clinical trial comparing a nebulized and a dry powder device for inhaled tobramycin in a CF population with chronic Pseudomonas aeruginosa (Pa) lung infection, aged 6 years and above (N=553). Reliability and validity of the questionnaire were investigated using Cronbach's α and multitrait-multimethod approach.

Results: The TSQM demonstrated very good reliability and construct validity: all Cronbach's α were above 0.86 and all items met the convergent and discriminant validity criteria. In multivariate regressions, higher patient satisfaction and lower perceived impact of side-effects were associated with better treatment compliance.

Conclusions: The TSQM showed very good measurement properties that strongly support its use to assess satisfaction of patients with CF taking inhaled antibiotics.