Seven RCTs (194 patients, range eight to 21) met the inclusion criteria. Three trials scored 7, three trials scored 5 and one trial scored 4 on the PEDro scale. Only one trial reported power calculation. One trial concealed treatment allocation. Five trials blinded outcome assessors, but not therapists or participants. Three trials used intention-to-treat (ITT) analysis.
From the narrative synthesis, breathlessness in patients with chronic obstructive pulmonary disease (COPD) during activities of daily living improved significantly for all the interventions except expiratory muscle training (which did not achieve statistical or clinical significance in two studies).
From the meta-analysis, inspiratory muscle training achieved a significantly better breathlessness score compared with control groups (MD 2.36, 95% CI 0.76 to 3.96; three RCTs; Ι²=43.4%).