General characteristics of participants in the development sample
| Controls (n=28 296) | Cases (n=15 159) | Unadjusted OR | (95% CI) | |||
|---|---|---|---|---|---|---|
| N | (%) | N | (%) | |||
| Mean age (SD) | 69.7 | (10.8) | 69.7 | (10.9) | – | |
| Males | 14 655 | (51.8) | 7849 | (51.8) | – | |
| Socioeconomic quintile* | ||||||
| 1 | 5035 | (17.8) | 2698 | (17.8) | – | |
| 2 | 4156 | (14.7) | 2237 | (14.8) | – | |
| 3 | 5079 | (17.9) | 2733 | (18.0) | – | |
| 4 | 6386 | (22.6) | 3429 | (22.6) | – | |
| 5 | 7640 | (27.0) | 4062 | (26.8) | – | |
| Smoking status† | ||||||
| Never | 14 693 | (51.9) | 2758 | (18.2) | 1 | |
| Former | 6013 | (21.3) | 4671 | (30.8) | 4.79 | (4.49 to 5.10) |
| Current | 4831 | (17.1) | 6961 | (45.9) | 8.99 | (8.43 to 9.59) |
| Missing | 2759 | (9.8) | 769 | (5.1) | 1.37 | (1.23 to 1.51) |
| BMI† | ||||||
| <18.5 | 5810 | (20.5) | 2917 | (19.2) | 0.80 | (0.76 to 0.85) |
| 18.5–25 | 8651 | (30.6) | 5232 | (34.5) | 1 | |
| 25–30 | 9299 | (32.9) | 4475 | (29.5) | 0.79 | (0.75 to 0.83) |
| >30 | 4536 | (16.0) | 2535 | (16.7) | 0.93 | (0.87 to 0.98) |
Unadjusted OR for association with COPD.
Unadjusted ORs for age, sex and socioeconomic status of general practice were not estimated as cases and controls were matched on these variables.
*1=least deprived. 2 3 4 5=most deprived. Based on Index of Multiple Deprivation score of general practice electoral ward.
†Closest to diagnosis.
BMI, body mass index; COPD, chronic obstructive pulmonary disease.