Table 2.
Accuracy of Various 6-minute-walk Distance Minimal Clinically Important Difference Cutoffs in Detecting Patients with Pulmonary Arterial Hypertension with a Change in Physical Component Score of at least Five
| 6MWD MCID Cutoff | Validation Data | Accuracy (95% CI)* |
|---|---|---|
| Population MCID of 33 m | PHAR G1 (n = 537) | 60.0 (55.8–64.1) |
| PHAR G2 (n = 354) | 68.1 (63.2–72.9) | |
| PHAR G3 (n = 225) | 66.7 (60.5–72.8) | |
| Population MCID stratified by baseline 6MWD: 63 m for patients with baseline 6MWD < 165 m; 34 m for patients with baseline 6MWD 165–440 m; and 19 m for patients with baseline 6MWD > 440 m | PHAR G1 (n = 537) | 59.2 (55.1–63.4) |
| PHAR G2 (n = 354) | 66.7 (61.8–71.6) | |
| PHAR G3 (n = 225) | 64.9 (58.7–71.1) | |
| Individual MCID obtained from a prediction model: Change in PCS (5) + baseline 6MWD | PHAR G1 (n = 537) | 60.1 (56.0–64.3) |
| PHAR G2 (n = 354) | 66.1 (61.2–71.0) | |
| PHAR G3 (n = 225) | 63.6 (57.3–69.8) | |
| Individual MCID obtained from a prediction model: Change in PCS (5) + baseline 6MWD + change in PCS (5) × baseline 6MWD | PHAR G1 (n = 537) | 59.6 (55.4–63.7) |
| PHAR G2 (n = 354) | 65.3 (60.3–70.2) | |
| PHAR G3 (n = 225) | 63.1 (56.8–69.4) |
Definition of abbreviations: 6MWD = 6-minute-walk distance; CI = confidence interval; G1: Between baseline and 1st follow-up visit; G2: Between 1st and 2nd follow-up visit; G3: Between 2nd and 3rd follow-up visit. MCID = minimal clinically important difference; PCS = physical component score.
*
Proportion of patients with and without a change in PCS ⩾ 5 who are correctly classified.