Table 2. Respiratory characteristics and exacerbations by frailty category.
| All participants | Normal spirometry | GOLD 1 | |||||||||||
| (A) | Robust | Prefrail | Frail | p * | Robust | Prefrail | Frail | p | Robust | Prefrail | Frail | p | |
| Characteristic | N | 912 | 1352 | 401 | 473 | 589 | 108 | 115 | 154 | 27 | |||
| Age | 2665 | 69 (7) | 70 (8) | 71 (9) | <0.001 | 68 (7) | 69 (8) | 71 (9) | <0.001 | 71 (8) | 73 (8) | 74 (10) | 0.27 |
| FEV1 % pred | 2646 | 85 (22) | 81 (24) | 65 (28) | <0.001 | 99 (13) | 100 (14) | 97 (12) | 0.20 | 92 (11) | 92 (10) | 92 (7) | 0.57 |
| Current Smoking | 2663 | 26.2% (239) | 34.2% (462) | 34.4% (138) | <0.001 | 22.8% (108) | 31.6% (186) | 34% (37) | 0.003 | (31%) 36 | (37%) 57 | (52%) 14 | 0.13 |
| Smoking Pack-Years | 2663 | 39 (20) | 43 (22) | 53 (27) | <0.001 | 35 (18) | 38 (21) | 42 (21) | 0.003 | 43 (22) | 48 (24) | 56 (30) | 0.055 |
| BODE score† | 2645 | 0 (0, 1) | 1 (0, 2) | 4 (2, 6) | <0.001 | 0 (0, 0) | 0 (0, 1) | 2 (1, 3) | <0.001 | 0 (0, 0) | 1 (0, 2) | 3 (2, 5) | <0.001 |
| MMRC score† | 2663 | 0 (0, 1) | 0 (0, 2) | 3 (1, 3) | <0.001 | 0 (0, 1) | 0 (0, 1) | 1 (0, 3) | <0.001 | 0 (0, 1) | 0 (0, 2) | 2 (0, 3) | <0.001 |
| Pi10 | 2433 | 2.16 (0.50) | 2.28 (0.55) | 2.64 (0.61) | <0.001 | 1.95 (0.40) | 1.99 (0.41) | 2.14 (0.43) | <0.001 | 2.08 (0.36) | 2.16 (0.42) | 2.47 (0.45) | <0.001 |
| (B) | |||||||||||||
| Outcome | N | 793 | 1122 | 307 | 407 | 489 | 80 | 104 | 127 | 21 | |||
| Annual exacerbation rate | 2222 | 0.14 (0.50) | 0.28 (0.75) | 0.67 (1.46) | <.001 | 0.10 (0.43) | 0.19 (0.71) | 0.39 (1.48) | 0.173 | 0.22 (0.68) | 0.20 (0.57) | 0.71 (2.56) | 0.78 |
| Any severe exacerbation | 2222 | 7.8% (62) | 13.4% (150) | 26.1% (80) | <.001 | 4.4% (18) | 7.4% (36) | 15.0% (12) | .002 | 12.5% (13) | 12.6% (16) | 24% (5) | 0.34 |
| Frequent exacerbations | 2222 | 3.4% (27) | 9.4% (105) | 22.1% (68) | <.001 | 2.0% (8) | 6.1% (30) | 11.3% (9) | <.001 | 5.8% (6) | 7.1% (9) | 10% (2) | 0.74 |
| GOLD 2–4 | PRISm | ||||||||||||
| Robust | Prefrail | Frail | p | Robust | Prefrail | Frail | p | ||||||
| Characteristic | 225 | 429 | 205 | 92 | 175 | 54 | |||||||
| Age | 70 (7) | 71 (8) | 73 (9) | 0.008 | 67 (8) | 67 (8) | 67 (8) | 0.86 | |||||
| FEV1 % pred | 59 (14) | 56 (16) | 43 (17) | <0.001 | 72 (8) | 70 (8) | 67 (10) | 0.01 | |||||
| Current Smoking | 27.6% (62) | 32.9% (141) | 30.7% (63) | 0.38 | 34% (31) | 44% (77) | 39% (21) | 0.26 | |||||
| Smoking Pack-Years | 45 (20) | 50 (23) | 58 (27) | <0.001 | 40 (21) | 38 (20) | 52 (27) | 0.003 | |||||
| BODE score† | 1 (0, 3) | 2 (1, 4) | 6 (4, 7) | <0.001 | 0 (0, 1) | 1 (0, 3) | 3 (3, 5) | <0.001 | |||||
| MMRC score† | 1 (0, 2) | 2 (0, 3) | 3 (3, 4) | <0.001 | 0 (0, 2) | 1 (0, 3) | 3 (2, 3) | <0.001 | |||||
| Pi10 | 2.54 (0.49) | 2.69 (0.52) | 2.91 (0.56) | <0.001 | 2.35 (0.50) | 2.43 (0.50) | 2.65 (0.55) | 0.003 | |||||
| Outcome | 198 | 358 | 160 | 78 | 145 | 42 | |||||||
| Annual exacerbation rate | 0.18 (0.48) | 0.45 (0.91) | 0.88 (1.38) | <.001 | 0.18 (0.59) | 0.20 (0.53) | 0.42 (0.85) | 0.026 | |||||
| Any severe exacerbation | 12.6% (25) | 22.6% (81) | 33.1% (53) | <.001 | 8% (6) | 11.7% (17) | 21% (9) | 0.087 | |||||
| Frequent exacerbations | 4.0% (8) | 15.9% (57) | 31.9% (51) | <.001 | 6% (5) | 6.2% (9) | 12% (5) | 0.44 | |||||
(A) Cross-sectional respiratory characteristics. (B) Longitudinal follow-up exacerbations (mean follow-up time: 2.8 years). Note that 19 participants did not have spirometry data reported, and not all participants had longitudinal follow-up data (N reported separately for 2A and 2B). Continuous variables reported as mean (standard deviation) unless otherwise specified; categorical variables reported as % (n). Abbreviations: GOLD: Global Initiative for Chronic Obstructive Lung Disease; PRISm: Preserved Ratio Impaired Spirometry; FEV1 % pred: Forced expiratory volume in 1 second % predicted; BODE: Body mass index, airflow Obstruction, Dyspnea, and Exercise capacity; MMRC: Modified Medical Research Council Dyspnea Scale; Pi10: standardized airway wall thickness on quantitative CT scan (mm). *p-value across frailty category (using Kruskal-Wallis rank sum test for continuous data, Pearson’s chi-squared test for categorical data with cell counts >5, and Fisher’s Exact test for categorical data with cell counts ≤5). †Median (IQR).