Table 2.
Primary outcomes at baseline, month 18, and change from baseline
| Baseline |
Month 18 |
Change from Baseline |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UC (n = 156) |
BI (n = 149) |
UC (n = 134) |
BI (n = 113) |
||||||||||
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | UC | BI | Between-Group P Value | Interaction Term P Value* | ||
| Overall (n = 305) | CRQ-D | 4.33 | 1.35 | 4.48 | 1.30 | 4.23 | 1.49 | 4.50 | 1.39 | −0.09 | −0.03 | 0.714 | 0.176 |
| 6MWD | 337.50 | 96.37 | 342.80 | 91.03 | 324.10 | 107.50 | 343.10 | 99.81 | −22.6† | −13.6† | 0.309 | 0.284 | |
| Stage 2 (n = 134) | CRQ-D | 4.60 | 1.39 | 4.76 | 1.21 | 4.57 | 1.53 | 4.86 | 1.26 | −0.07 | 0.08 | 0.552 | 0.381 |
| 6MWD | 360.80 | 91.57 | 368.90 | 84.89 | 336.00 | 104.40 | 380.70 | 90.11 | −28.68† | 5.34 | 0.003 | 0.006 | |
| Stage 3 (n = 130) | CRQ-D | 4.19 | 1.37 | 4.40 | 1.37 | 4.17 | 1.37 | 4.43 | 1.35 | 0.06 | 0.00 | 0.844 | 0.660 |
| 6MWD | 321.80 | 97.71 | 338.00 | 87.77 | 327.90 | 112.30 | 314.30 | 98.81 | −9.96 | −34.17† | 0.089 | 0.178 | |
| Stage 4 (n = 41) | CRQ-D | 3.78 | 0.96 | 3.91 | 1.10 | 3.25 | 1.19 | 2.96 | 1.27 | −0.55† | −0.79 | 0.655 | 0.052 |
| 6MWD | 299.90 | 92.33 | 279.30 | 91.52 | 275.00 | 98.29 | 291.10 | 90.14 | −29.66 | −9.49 | 0.573 | 0.516 | |
Definition of abbreviations: 6MWD = 6-minute-walk distance; BI = behavioral intervention; CRQ-D = Chronic Respiratory Questionnaire dyspnea domain; GOLD = Global Initiative for Chronic Obstructive Lung Disease; UC = usual care.
Repeated-measures analysis of variance model: Outcome = Group + Time + Group × Time + Age + Sex + GOLD stage + Charlson comorbidity index + Baseline readiness to change physical activity score. Interaction term P value was based on the repeated-measures analysis of variance group × time interaction term. Interaction can be interpreted as between-group differences in the relationship between time and outcome.
Statistically significant difference from baseline values at the α = 0.05 level.