Smartphone messenger-supported versus self-managed inspiratory muscle training after lung resection in high-risk patients: a pilot randomised controlled trial

Inspiratory muscle training (IMT) is used after lung resection, but its benefits may depend on supervision, adherence, and structured load progression, which are difficult to provide through repeated outpatient visits. This pilot report focuses on implementation feasibility, particularly remote support delivery and adherence, and explores preliminary clinical effects of adding smartphone messenger-based support to standardised self-managed home-based IMT in high-risk patients after lung resection. In this single-centre pilot randomised controlled trial, 58 patients meeting predefined high-risk criteria after lung resection were randomised 1:1 to a telerehabilitation group (TG) or a self-management group (SMG). Both groups received the same face-to-face instruction and followed the same 6-week IMT protocol. The TG additionally received asynchronous monitoring, symptom checks, and feedback through a smartphone messenger application, with telephone support when needed. The prespecified primary clinical outcome was functional exercise capacity assessed using the 6-minute walk test (6MWT). Feasibility, safety, and intervention fidelity were summarised descriptively, and exploratory longitudinal clinical outcomes were analysed using linear mixed-effects models. Forty-seven of 58 participants (81.0%) contributed 6MWT data to the longitudinal analysis. The 6-week intervention was completed by 25 of 30 participants (83.3%) in the TG and 20 of 28 (71.4%) in the SMG. Among TG completers, delivery was message only in 44.0%, message plus telephone in 48.0%, and primarily telephone-based in 8.0%. No intervention-related serious adverse events were reported. Among intervention completers, mean adherence was 85.3% in the TG ( n = 25) and 69.3% in the SMG ( n = 20; p = 0.090). The 6MWT, maximal inspiratory pressure, FEV1% predicted, and Physical Activity Scale for the Elderly score improved over time in both groups, with no significant group effects or group-by-time interactions. Cardiopulmonary exercise testing outcomes at follow-up did not differ significantly between groups. The findings support the practical feasibility of messenger-supported IMT in this pilot sample. No clear additional clinical benefit over standardised self-managed home-based IMT was demonstrated. The feasibility data and preliminary clinical estimates can inform future trial planning. ClinicalTrials.gov (NCT07455552; https://clinicaltrials.gov/study/NCT07455552 ). First submitted: 9 July 2025; first posted: 6 March 2026 (retrospectively registered).