Excellent adherence and no contamination by physiotherapists involved in a randomized controlled trial on reactivation of COPD patients: a qualitative process evaluation study

Abstract

Tanja W Effing,1,2 Manon Krabbenbos,3 Marcel E Pieterse,4 Paul DLPM van der Valk,3 Gerhard A Zielhuis,5 Huib AM Kerstjens,6 Job van der Palen,371Repatriation General Hospital, Department of Respiratory Medicine, Daw Park, 2Flinders University, School of Medicine, Adelaide, South Australia, Australia; 3Medisch Spectrum Twente, Department of Pulmonology, Enschede, 4Department of Psychology, Health and Technology, Enschede, 5Department of Epidemiology, Biostatistics and HTA, Radboud University Nijmegen, Nijmegen, 6Department of Pulmonology, University Medical Center Groningen, University of Groningen, Groningen, 7Department of Research Methodology, Measurement and Data Analysis, University of Twente, The Netherlands Objective: To assess the adherence of physiotherapists to the study protocol and the occurrence of contamination bias during the course of a randomized controlled trial with a recruitment period of 2 years and a 1-year follow-up (COPE-II study).Study design and setting: In the COPE-II study, intervention patients received a standardized physiotherapeutic reactivation intervention (COPE-active) and control patients received usual care. The latter could include regular physiotherapy treatment. Information about the adherence of physiotherapists with the study protocol was collected by performing a single interview with both intervention and control patients. Patients were only interviewed when they were currently receiving physiotherapy. Interviews were performed during two separate time periods, 10 months apart. Nine characteristics of the COPE-active intervention were scored. Scores were converted into percentages (0%, no aspects of COPE-active; 100%, full implementation of COPE-active).Results: Fifty-one patients were interviewed (first period: intervention n = 14 and control n = 10; second period: intervention n = 18 and control n = 9). Adherence with the COPE-active protocol was high (median scores: period 1, 96.8%; period 2, 92.1%), and large contrasts in scores between the intervention and control group were found (period 1: 96.8% versus 22.7%; period 2: 92.1% versus 25.0%). The scores of patients treated by seven physiotherapists who trained patients of both study groups were similar to the scores of patients treated by physiotherapists who only trained patients of one study group.Conclusion: The adherence of physiotherapists with the COPE-active protocol was high, remained unchanged over time, and no obvious contamination bias occurred.Keywords: physiotherapy, guideline adherence, compliance, bias, randomized controlled trial, chronic obstructive pulmonary diseas