Validation of an Instrument Measuring Patient Satisfaction with Chest Physiotherapy Techniques in Cystic Fibrosis

Objectives: Chest physiotherapy (CPT) has been an important part of cystic fibrosis (CF) treatment regimens for > 40 years. Techniques with different perceived costs, benefits, and patient satisfaction exist. An instrument measuring patient satisfaction with CPT has not been reported. Our goal was to develop and validate such an instrument.

Design: A cross-sectional survey sent to 349 patients seen at a large, urban, academic CF care center. The two-page survey asked 17 questions related to CPT satisfaction (efficacy, convenience, comfort, overall satisfaction), followed by 4 general CF-care questions (disease severity, importance of therapies, prescribed vs missed therapies). A 5-point Likert-type scale was used for responses. Psychometric analysis included itemetric performance, confirmatory factor analysis, test-retest reliability, and evaluation of subject's responses to the general CF-care questions.

Results: One hundred twenty-nine individuals returned completed surveys (39%; 66 males and 63 females; age range, 2 months to 47 years). FEV(1)values were 21 to 155% predicted (mean, 76%; n = 82). Disease severity was as follows: 60 mild, 47 moderate, and 14 severe. Seventy-nine subjects used postural drainage, percussion, and vibration (PDPV), 21 used a flutter device, and 14 used high-frequency chest wall oscillation (HFCWO). Five subjects used more than one technique. Internal consistency analysis found an overall coefficient alpha of 0.87 (range, 0.74 to 0.89 for four domains). Factor analysis demonstrated domains for efficacy, convenience, comfort, and overall satisfaction. Mean total satisfaction scores differed significantly among therapies (R(2) = 0. 118; F[ 2,111] = 7.56; p = 0.0008): PDPV, 3.8 (SD = 0.6); Flutter, 4. 3 (SD = 0.5); and HFCWO, 4.1 (SD = 0.5). Therapies also differed significantly on all subscores. Perceived importance of CPT and compliance with CPT increased linearly with disease severity. Overall satisfaction was positively correlated with CPT compliance.

Conclusions: The CPT satisfaction survey has good reliability and content validity. Significant differences in patient satisfaction exist among therapies. Sicker patients recognize the importance of, and demonstrate better compliance with prescribed CPT. Increased satisfaction is associated with better compliance with therapy.