Effect of Inspiratory Muscle Training on Cough Strength in Older People With Frailty: A Single-Blind Randomized Controlled Trial.

Abstract

To investigate the effect of inspiratory muscle training (IMT) on cough strength in older people with frailty. Single-blind randomized controlled trial. Day health care centers at 2 sites. Older people with frailty (N=60). Eligible people were randomly assigned to receive IMT program in addition to general exercise training (IMT group), or general exercise training alone (control group). The IMT group performed training using a threshold IMT device with the load set at 30% of maximum inspiratory mouth pressure in addition to the general exercise training program throughout the 8 weeks. The IMT took place twice a day and each session consisted of 30 breaths. Primary outcome was cough strength, measured as the cough peak flow (CPF), at the beginning and the end of the program. Data from 52 participants (26 in each group) were available for the analysis. The mean age was 82.6 years; 33% were men. The change in CPF at the end of the program was 28.7±44.4 L/min in the IMT group and -7.4±26.6 L/min in the control group. A linear regression model showed that the presence or absence of IMT was associated with changes in CPF (mean difference between groups, 36.3; 95% confidence interval, 16.7-55.9; effect size, 0.99). IMT may be a useful intervention to improve cough strength in frail older people.