Validation of the treatment satisfaction questionnaire for Crohn's disease (TSQ-C)

Abstract

Treatment satisfaction is used to capture the full impact of disease on patients' lives. Currently, no instruments exist to evaluate satisfaction with pharmacologic therapy in patients with Crohn's disease (CD). The purpose of this study was to evaluate the psychometric properties of a treatment satisfaction questionnaire for CD (TSQ-C). The 36-item questionnaire was completed by CD patients who reported taking 5-aminosalicylic acid derivatives to treat their CD. Measures used in the validation study were the Inflammatory Bowel Disease Questionnaire (IBDQ), Crohn's Work Activity Impairment Index (CWAII), and patient reports of clinical indicators (e.g., number of active flares and medications taken). Exploratory factor analysis was used to evaluate the items and subscale structure. Internal consistency reliability and concurrent and discriminant validity were assessed using Cronbach's alpha, Pearson correlation coefficients, and analysis of variance. A total of 813 CD patients participated, with the majority being Caucasian (95.9%), female (67.0%), and >34 years old (86.1%). Patient-rated severity of CD was mild (49.3%), moderate (41.7%), and severe (7.5%). The final TSQ-C consisted of 32 items, with six subscales (Symptoms, Satisfaction, Expectations, Physician Relationships, Bother, and Cost), with each subscale score ranging from 1 to 6. Cronbach's alpha values ranged from 0.63 (Cost) to 0.94 (Symptoms). Strong correlations were observed among the IBDQ, CWAII, and the Satisfaction and Symptoms subscales of the TSQ-C. TSQ-C subscales, particularly Symptoms and Satisfaction, significantly discriminated among levels of number of flares per year, patient-rated disease severity, and number of medication classes. The TSQ-C demonstrated excellent validity and reliability and appears to be a useful tool for evaluating satisfaction with pharmacologic therapy among patients with CD.