Table 1.
Summary of patient demographics by zFEV1.
| Clinically normal range | Clinically abnormal range | ||||
|---|---|---|---|---|---|
| zFEV1 ≥0 (n=173) | zFEV1 <0 to -1 (n=326) | zFEV1 <-1 to -2 (n=469) | zFEV1 <-2 (n=766) | ||
| Median (IQR) | |||||
| FEV1 (% predicted) | 107•0 (102•8-112•3) | 91•4 (88•5-95•2) | 78•7 (74•8-82•2) | 54•0 (40•9-63•7) | |
| FVC (% predicted) | 107•4 (100•6-112•6) | 93•3 (88•1-98•9) | 82•2 (76•8-88•6) | 66•9 (56•7-75•9) | |
| FEV1/FVC | 0•82 (0•78-0•86) | 0•80 (0•75-0•83) | 0•77 (0•70-0•82) | 0•65 (0•52-0•75) | |
| n (%) < LLN (Z <-1.64) | 3 (<1%) | 20 (<1%) | 76 (16%) | 450 (59%) | |
| n (%) | |||||
| Sex | |||||
| Female | 108 (62%) | 192 (59%) | 281 (59•9%) | 432 (56%) | |
| Male | 65 (38%) | 134 (41%) | 188 (40•1%) | 334 (44%) | |
| First Nations | 97 (56%) | 200 (61%) | 319 (68•0%) | 497 (65%) | |
| Age (years) | 53 (40-63) | 55 (45-66) | 57 (46-68) | 59 (51-68) | |
| BMI (kg/m2) | |||||
| Underweight (<18•5) | 1 (<0•1%) | 10 (<1%) | 21 (5%) | 49 (6%) | |
| Healthy (18•5-24•9) | |||||
| 33 (19%) | 63 (19%) | 70 (15%) | 167 (22%) | ||
| Overweight (25-29•9) | |||||
| 49 (28%) | 75 (23%) | 111 (24%) | 182 (24%) | ||
| Obese (≥30) | |||||
| 90 (52%) | 178 (55%) | 267 (57%) | 368 (48%) | ||
| Smoking (n=1571) | |||||
| Current | 27 (16%) | 97 (30%) | 175 (37%) | 303 (40%) | |
| Former | |||||
| 43 (25%) | 98 (30%) | 151 (32%) | 270 (35%) | ||
| Never | 76 (44%) | 93 (29%) | 115 (25%) | 123 (16%) | |
| Household smoke (n=1396) | |||||
| Yes | |||||
| 43 (25%) | 96 (29%) | 150 (32%) | 280 (37%) | ||
| No | 88 (51%) | 158 (49%) | 247 (53%) | 330 (43%) | |
| Hypertension | 40 (23%) | 101 (31%) | 174 (37%) | 307 (40%) | |
| Chronic respiratory disease | 104 (60%) | 218 (67%) | 360 (77%) | 663 (87%) | |
| Cardiovascular disease | 29 (17%) | 48 (15%) | 96 (21%) | 218 (29%) | |
| Cancers | 13 (6%) | 14 (4%) | 14 (<1%) | 44 (6%) | |
| Deaths | 1 (<1%) | 15 (5%) | 32 (7%) | 141 (18%) | |
Clinically normal range encompasses Z-scores >=-1.64.