| Expiratory muscle weakness | ||
| Diagnosed as weak (%) | SE (95% CI) | |
| (1) Pemax | 38.3 (23/60) | 6.33 (25.7 to 51.0) |
| (2) Cough Pgas | 36.7 (22/60) | 6.27 (24.1 to 49.2) |
| (3) Twitch T10 | 28.3 (17/60) | 5.87 (16.6 to 40.1) |
| (4) Pemax + cough Pgas | 26.7 (16/60) | 5.76 (15.1 to 38.2) |
| (5) Pemax + cough Pgas + Twitch T10 | 16.7 (10/60) | 4.85 (8.0 to 26.4) |
Pemax, maximum expiratory pressure; Pgas, gastric pressure; SE, standard error of the mean; CI, confidence interval.
The combination of Pemax, cough Pgas and Twitch T10 diagnosed 16.7% of the patients to have expiratory muscle weakness and reduced the number of falsely positive diagnoses compared with Pemax and cough Pgas. The relative reduction in false diagnoses was 56.4% compared with Pemax and 54.5% compared with cough Pgas.