Table 2.
Comparison of mutually adjusted spirometric indices to predict all-cause mortality in national health surveys (all spirograms) and in UK Biobank (comparing all usable spirograms with best quality spirograms)
| Subset analysed | z-score in model (plus covariates) | HSE–SHS white lifelong non-smokers, 40–69 years at entry | Biobank white lifelong non-smokers, 40–69 years at entry | ||||
| Total N (deaths) | HR (95% CI) alone | HR (95% CI) joint | Total N (deaths) | HR (95% CI) alone | HR (95% CI) joint | ||
| All usable spirograms | FEV1 alone | 6579 (500) | 1.17 (1.09 to 1.25) | 149 343 (2401) | 1.21 (1.17 to 1.26) | ||
| FEV1 adj FEV/FVC | 1.20 (1.11 to 1.29) | 1.26 (1.21 to 1.31) | |||||
| FEV/FVC adj FEV1 | 0.94 (0.87 to 1.01) | 0.90 (0.85 to 0.94) | |||||
| All usable spirograms | FVC alone | 6579 (500) | 1.19 (1.10 to 1.28) | 149 343 (2401) | 1.24 (1.19 to 1.29) | ||
| FVC adj FEV/FVC | 1.19 (1.11 to 1.28) | 1.24 (1.19 to 1.29) | |||||
| FEV/FVC adj FVC | 1.02 (0.95 to 1.10) | 1.02 (0.97 to 1.07) | |||||
| Best quality spirograms | FEV1 alone | (No data) | 102 945 (1583) | 1.23 (1.18 to 1.29) | |||
| FEV1 adj FEV/FVC | 1.29 (1.23 to 1.36) | ||||||
| FEV/FVC adj FEV1 | 0.86 (0.81 to 0.91) | ||||||
| Best quality spirograms | FVC alone | (No data) | 102 945 (1583) | 1.29 (1.23 to 1.35) | |||
| FVC adj FEV/FVC | 1.29 (1.23 to 1.35) | ||||||
| FEV/FVC adj FVC | 0.98 (0.93 to 1.04) | ||||||
Spirometric indices (FEV1, FVC and FEV1:FVC ratio) are modelled as z-scores derived from the Global Lung Initiative 2012 reference equations for whites. All HRs are expressed per unit decrement in z-score, adjusted for age, sex, height, socioeconomic status, geographical region and survey year.
FEV1, one-second forced expiratory volume; FVC, forced vital capacity; HSE, Health Survey for England; SHS, Scottish Health Survey.