Table 2.
Factors associated with a minimum clinically important difference in 6 min walk test according to a distribution-based definition. Distribution-based approach following Cohen’s moderate effect size, 41 m in this study cohort
| Minimum clinical important difference (N = 43) | No minimum difference (N = 46) | Scale factor | Unadjusted odds ratio of MCID | |
|---|---|---|---|---|
| Baseline | Baseline | |||
| (N = 43) | (N = 46) | |||
| Demographics | ||||
| Age (year, mean ± standard deviation) | 37.3 (± 7.6) | 37.1 (± 8.6) | 1.00 (0.95, 1.06) | |
| Male sex (n, %) | 24 (56%) | 28 (61%) | 0.81 (0.35, 1.89) | |
| Ever smoke (n, %) | 19 (44%) | 13 (28%) | 2.58 (1.04, 6.63) | |
| Clinical characteristics (mean ± standard deviation) | ||||
| Six-minute walk distance (meters)a | 357 (± 60) | 427 (± 59) | 10 m | 0.83 (0.76, 0.90) |
| Sputum culture positivity* (count (%)) | 16 (37%) | 23 (50%) | 0.59 (0.25, 1.37) | |
| Time between anti-tuberculosis treatment and antiretroviral therapy (days) | 33 (± 20) | 26 (± 16) | 1.02 (1.00, 1.05) | |
| Body mass index (kg/m2) | 19.3 (± 2.4) | 20.4 (± 4.1) | 0.90 (0.76, 1.03) | |
| CD4 count (cells/mm3) | 127 (± 135) | 165 (± 130) | 10 cells/mm3 | 0.98 (0.94, 1.01) |
| Plasma HIV RNA level (log10 (copies/mm3)) | 5.4 (± 1.0) | 5.2 (± 1.1) | 1.14 (0.75, 1.77) | |
| Forced vital capacity (FVC, liters) | 3.0 (± 0.8) | 3.2 (± 0.9) | 100 mL | 0.97 (0.92, 1.02) |
| FVC predicted (%)a | 81.2 (± 19.6) | 85.7 (± 18.3) | 5% | 0.94 (0.83, 1.06) |
| Forced expiratory volume in 1 s (FEV1, liters) | 2.2 (± 0.7) | 2.5 (± 0.7) | 100 mL | 0.94 (0.87, 1.00) |
| FEV1 predicted (%) | 72.7 (± 19.5) | 80.5 (± 18.7) | 5% | 0.90 (0.79, 1.01) |
| COPD** Assessment test total score | 8.0 (± 6.7) | 6.6 (± 6.0) | 1.04 (0.97, 1.11) | |
| Biomarkers (mean ± standard deviation) | ||||
| Collagen Ia (pg/L)a | 2080 (± 1170) | 2930 (± 2230) | 1000 pg/L | 0.72 (0.49, 0.96) |
| TIMP1 (pg/L)a | 208,000 (± 110,000) | 152,000 (± 95,500) | 10000 pg/L | 1.05 (1.01, 1.10) |
| CCL2 (pg/L) | 224 (± 109) | 236 (± 105) | 100 pg/L | 0.89 (0.59, 1.34) |
| CXCL11 (pg/L) | 109 (± 88.1) | 94.1 (± 86.0) | 10 pg/L | 1.02 (0.97, 1.07) |
| IL8 (pg/L) | 13.0 (± 6.94) | 13.0 (± 7.85) | 1 pg/L | 1.00 (0.94, 1.06) |
| MMP1 (pg/L) | 990 (± 595) | 1090 (± 972) | 100 pg/L | 0.98 (0.93, 1.04) |
| VCAM1 (pg/L) | 2,450,000 (± 1,550,000) | 2,040,000 (± 1,030,000) | 1000000 pg/L | 1.28 (0.92, 1.85) |
| CXCL10 (pg/L) | 506 (± 339) | 561 (± 828) | 100 pg/L | 0.99 (0.91, 1.06) |
| IL6 (pg/L) | 6.3 (± 9.4) | 8.3 (± 12.3) | 10 pg/L | 0.83 (0.49, 1.25) |
| M-CSF (pg/L)a | 213 (± 130) | 162 (± 124) | 10 pg/L | 1.03 (1.00, 1.07) |
| Plasminogen activator (pg/L) | 955 (± 335) | 907 (± 304) | 100 pg/L | 1.05 (0.92, 1.21) |
| VEGF (pg/L) | 17.1 (± 9.9) | 16.9 (± 9.2) | 1 pg/L | 1.00 (0.96, 1.05) |
Missing—11% in ever smoke, BMI, CD4, viral load, FVC, FVC pred, FEV1, and FEV1pred; 4% in time to ART; and 5% in biomarkers
*Study recruitment at baseline was within 30 days from anti-TB treatment initiation, and hence the culture results may already be conversed to negative
**COPD, Chronic Obstructive Pulmonary Disease
aStatistically significant difference in mean values at baseline at alpha = 0.05