Effects of a pre-operative home-based inspiratory muscle training programme on perceived health-related quality of life in patients undergoing coronary artery bypass graft surgery

Abstract Objectives Pre-operative inspiratory muscle training has been shown to decrease the incidence of postoperative pneumonia and length of hospital stay in patients undergoing coronary artery bypass graft surgery (CABG). This study investigated if this decrease acted as a mediator on the time course of quality of life. Design Complementary analyses of a published randomised controlled trial. Setting and participants The initial trial included patients awaiting CABG surgery at a Dutch university hospital. The secondary analyses used data from the initial trial for patients who had completed at least one quality-of-life questionnaire. Methods Participants were allocated at random to the intervention group or the usual care group. The intervention group followed a home-based pre-operative inspiratory muscle training programme. Quality of life was measured at five time points. Between-group differences in quality-of-life scores were analysed using mixed linear modelling. Results The secondary analyses used data for 235 patients. In line with the initial trial, pneumonia and length of hospital stay were decreased significantly in the intervention group. The time courses for all patients showed significant improvements in quality of life after surgery compared with baseline. No significant differences in quality of life were observed over time between the two groups. Conclusion Despite decreased incidence of pneumonia and length of hospital stay in the intervention group, this study did not find any improvements in quality of life due to the pre-operative home-based inspiratory muscle training programme. Clinical trial registration number ISRCTN17691887.