| Inspiratory muscle weakness | ||
| Diagnosed as weak (%) | SE (95% CI) | |
| (1) Pimax | 40.1 (73/182) | 3.64 (32.9 to 47.3) |
| (2) Sniff Pnasal | 41.8 (76/182) | 3.67 (34.5 to 41.8) |
| (3) Sniff Poes | 37.9 (69/182) | 3.61 (30.8 to 45.0) |
| (4) Pimax + Sniff Pnasal | 32.4 (59/182) | 3.48 (25.6 to 39.3) |
| (5) Pimax + Sniff Poes | 29.7 (54/182) | 3.40 (23.0 to 36.4) |
| (6) Pimax + Sniff Pnasal + Sniff Poes | 29.1 (53/182) | 3.38 (22.5 to 35.8) |
Pimax, maximum inspiratory pressure; Pnasal, nasal pressure; Poes, oesophageal pressure; Pdi, transdiaphragmatic pressure, Pemax, maximum expiratory pressure; Pgas, gastric pressure; SE, standard error of the mean; CI, confidence interval.
Combination of Pimax, Sniff Pnasal and Sniff Poes results reduces diagnosis of global inspiratory weakness to 29.1%. This is a relative reduction of 27.4% compared with Pimax alone, 30.4% reduction compared with Sniff Pnasal alone and 23.2% reduction compared with Sniff Poes alone. A combination of two tests (4 and 5) reduced the rate to 32.4% and 29.7%, respectively. There was no significant difference between the single tests. Performing all three tests achieved the highest precision.