Death rates, adjusted HRs, and standardised mortality ratios (SMRs) with 95% CIs for the associations of spirometric Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades and ABCD groups with all-cause mortality among participants with chronic obstructive pulmonary disease (COPD) in the HUNT2 Lung Study
| COPD classification | Person-years | Observed deaths | Death rate* | (95% CI) | Age-adjusted HR† | Multi-adjusted HR‡ | (95% CI)‡ | Expected deaths | SMR§ | (95% CI)§ |
|---|---|---|---|---|---|---|---|---|---|---|
| Women | ||||||||||
| GOLD grades¶ (n=584) | 7393 | 273 | 36.93 | (32.80 to 41.58) | ||||||
| GOLD 1 | 2366 | 59 | 24.94 | (19.32 to 32.19) | 1.00 | 1.00 | (Reference) | 79 | 0.75 | (0.59 to 0.95) |
| GOLD 2 | 4341 | 155 | 35.70 | (30.50 to 41.79) | 2.32 | 2.29 | (1.66 to 3.16) | 91 | 1.70 | (1.46 to 1.99) |
| GOLD 3 | 583 | 52 | 89.12 | (67.91 to 116.96) | 6.48 | 6.23 | (4.15 to 9.36) | 11 | 4.72 | (3.62 to 6.08) |
| GOLD 4 | 102 | 7 | 68.55 | (32.68 to 143.78) | 6.90 | 6.97 | (3.05 to 15.91) | 1 | 5.15 | (2.45 to 9.92) |
| ABCD groups** (n=468) | 5918 | 217 | 36.67 | (32.10 to 41.89) | ||||||
| Group A | 3667 | 115 | 31.36 | (26.12 to 37.65) | 1.00 | 1.00 | (Reference) | 96 | 1.19 | (0.99 to 1.44) |
| Group B | 1268 | 42 | 33.12 | (24.47 to 44.81) | 1.22 | 1.12 | (0.78 to 1.62) | 27 | 1.56 | (1.18 to 2.08) |
| Group C | 453 | 28 | 61.85 | (42.70 to 89.58) | 2.08 | 2.47 | (1.62 to 3.79) | 11 | 2.55 | (1.62 to 3.94) |
| Group D | 530 | 32 | 60.41 | (42.72 to 85.42) | 2.14 | 2.43 | (1.62 to 3.66) | 12 | 2.62 | (1.77 to 3.82) |
| Men | ||||||||||
| GOLD grades¶ (n=956) | 10 757 | 564 | 52.43 | (48.28 to 56.94) | ||||||
| GOLD 1 | 3259 | 108 | 33.14 | (27.44 to 40.02) | 1.00 | 1.00 | (Reference) | 119 | 0.91 | (0.76 to 1.08) |
| GOLD 2 | 6142 | 327 | 53.24 | (47.77 to 59.34) | 1.51 | 1.44 | (1.15 to 1.80) | 246 | 1.33 | (1.20 to 1.47) |
| GOLD 3 | 1189 | 110 | 92.51 | (76.74 to 111.51) | 2.03 | 2.04 | (1.56 to 2.68) | 62 | 1.77 | (1.47 to 2.12) |
| GOLD 4 | 167 | 19 | 113.58 | (72.45 to 178.07) | 4.28 | 4.24 | (2.57 to 7.00) | 5 | 3.47 | (2.70 to 4.39) |
| ABCD groups** (n=736) | 8350 | 436 | 52.22 | (47.54 to 57.36) | ||||||
| Group A | 5437 | 242 | 44.51 | (39.24 to 50.49) | 1.00 | 1.00 | (Reference) | 196 | 1.24 | (1.10 to 1.39) |
| Group B | 1310 | 72 | 54.97 | (43.63 to 69.25) | 0.97 | 0.89 | (0.68 to 1.16) | 61 | 1.18 | (0.95 to 1.47) |
| Group C | 1041 | 69 | 66.27 | (52.34 to 83.90) | 1.08 | 1.10 | (0.84 to 1.44) | 52 | 1.32 | (1.04 to 1.68) |
| Group D | 562 | 53 | 94.38 | (72.10 to 123.53) | 1.63 | 1.70 | (1.25 to 2.29) | 27 | 1.98 | (1.50 to 2.59) |
*Per 1000 person-years.
†Adjusted for age (as the time scale).
‡Adjusted for age (as the time scale), smoking (never, former, current, unknown) and education (<10, ≥10 years, unknown).
§Standardised according to sex, 5-year age bands and 5-year calendar periods.
¶COPD defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.70 and graded as follows; GOLD 1=per cent predicted FEV1 (ppFEV1) ≥80; GOLD 2=50≤ ppFEV1 <80; GOLD 3=30≤ ppFEV1 <50; GOLD 4=ppFEV1 <30.
**ABCD groups defined as follows; A=dyspnoea ≤grade 1, GOLD 1 or 2, and ≤1 exacerbation last 12 months; B=dyspnoea ≥grade 2, GOLD 1 or 2, and ≤1 exacerbation last 12 months; C=dyspnoea ≤grade 1, and GOLD 3 or 4 or ≥2 exacerbations last 12 months; D=dyspnoea ≥grade 2, and GOLD 3 or 4 or ≥2 exacerbations last 12 months.