Table 1.
Demographic characteristics and inspiratory muscle performance of the psychometric testing samples
| Variables | Test–retest reliability (n=21)
|
Known-groups validity (n=81)
|
Convergent validity: 6MWT (n=47)
|
Convergent validity: mMRC (n=53)
|
||||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | |
| Age (years) | 68.7 | 6.2 | 69.9 | 5.7 | 70.3 | 5.5 | 69.5 | 5.2 |
| Height (cm) | 173.9 | 8.1 | 175.5 | 7.7 | 175.3 | 8.1 | 176.1 | 8.3 |
| Weight (kg) | 83.7 | 26.2 | 80.9 | 19.2 | 79.0 | 19.4 | 80.9 | 21.0 |
| Post-BD FEV1 (% predicted) | 48.1 | 21.2 | 46.5 | 16.9 | 43.5 | 16.4 | 47.3 | 16.7 |
| MIP (cmH2O) | 78.1 | 25.4 | 77.5 | 23 | 74.8 | 17.9 | 75.8 | 19.7 |
| SMIP (PTU) | 387.3 | 160.7 | 403.8 | 135.5 | 392.9 | 115.2 | 410.6 | 117.9 |
| ID (seconds) | 9.6 | 3.7 | 10 | 2.8 | 43.5 | 2.4 | 10.5 | 2.5 |
Abbreviations: 6MWT, 6-minute walk test; ID, inspiratory duration; MIP, maximal inspiratory pressure; mMRC, modified Medical Research Council dyspnea scale; Post-BD FEV1, post-bronchodilator forced expiratory volume in the first second; PTU, pressure time units; SMIP, sustained maximal inspiratory pressure.