Results of multinomial logistic regressions for combined outcome variable based on diagnosed COPD and potential airflow obstruction using FTs and LLN spirometric criteria among persons aged 40–95 years, HSE 2010 and UKHLS Wave 2 (2010–2012)*
| Characteristics | FTs† | LLN‡ | |||||
|---|---|---|---|---|---|---|---|
| Neither diagnosed nor obstructive spirometry as reference | Neither diagnosed nor obstructive spirometry as reference | ||||||
| Diagnosed alone | Obstructive spirometry alone | Diagnosed and obstructive spirometry | Diagnosed alone | Obstructive spirometry alone | Diagnosed and obstructive spirometry | ||
| n | RRR (95% CI)§ | RRR (95% CI)§ | RRR (95% CI)§ | RRR (95% CI)§ | RRR (95% CI)§ | RRR (95% CI)§ | |
| Sex | |||||||
| Females¶ | 4372 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Males | 3231 | 0.49 (0.31 to 0.79) | 1.31 (1.16 to 1.49) | 2.23 (1.34 to 3.71) | 0.52 (0.34 to 0.81) | 1.05 (0.90 to 1.23) | 2.15 (1.25 to 3.71) |
| p Value | 0.003 | <0.001 | 0.002 | 0.004 | 0.543 | 0.006 | |
| Age-group | |||||||
| 40–54¶ | 3416 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 55–64 | 2022 | 1.26 (0.76 to 2.09) | 2.08 (1.76 to 2.46) | 4.06 (2.11 to 7.79) | 1.34 (0.83 to 2.16) | 1.09 (0.90 to 1.33) | 2.91 (1.49 to 5.68) |
| 65–74 | 1451 | 1.47 (0.84 to 2.55) | 3.05 (2.56 to 3.63) | 4.78 (2.38 to 9.57) | 1.27 (0.74 to 2.15) | 1.02 (0.82 to 1.27) | 3.12 (1.53 to 6.36) |
| 75+ | 714 | 1.95 (0.69 to 5.51) | 5.89 (4.76 to 7.29) | 7.55 (3.35 to 17.02) | 1.60 (0.67 to 3.81) | 1.42 (1.08 to 1.87) | 3.47 (1.43 to 8.40) |
| p Value | 0.388 | <0.001 | <0.001 | 0.535 | 0.085 | <0.001 | |
| Pack-years** | |||||||
| 0–0.9¶ | 4165 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 1–19.9 | 1835 | 1.08 (0.61 to 1.92) | 1.67 (1.42 to 1.96) | 2.84 (1.30 to 6.23) | 1.16 (0.68 to 2.00) | 2.02 (1.63 to 2.50) | 2.58 (1.10 to 6.01) |
| 20–49.9 | 1269 | 3.05 (1.68 to 5.54) | 3.18 (2.70 to 3.74) | 6.70 (3.35 to 13.40) | 2.98 (1.72 to 5.16) | 4.23 (3.44 to 5.20) | 5.74 (2.70 to 12.20) |
| 50+ | 334 | 3.94 (1.70 to 9.13) | 4.15 (3.13 to 5.49) | 18.50 (8.41 to 40.70) | 3.87 (1.81 to 8.29) | 6.83 (4.98 to 9.37) | 17.23 (7.37 to 40.28) |
| p Value | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | |
| NS-SEC** | |||||||
| Professional¶ | 3047 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Intermediate | 1855 | 0.76 (0.45 to 1.30) | 1.20 (1.02 to 1.41) | 1.84 (0.87 to 3.87) | 0.83 (0.50 to 1.40) | 1.19 (0.97 to 1.47) | 1.57 (0.72 to 3.44) |
| Routine | 2701 | 0.93 (0.59 to 1.48) | 1.31 (1.12 to 1.53) | 3.65 (1.89 to 7.06) | 1.08 (0.70 to 1.67) | 1.54 (1.27 to 1.87) | 3.37 (1.70 to 6.68) |
| p Value | 0.612 | 0.002 | <0.001 | 0.632 | <0.001 | <0.001 | |
| Sample | |||||||
| UKHLS¶ | 5675 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| HSE | 1928 | 2.38 (1.54 to 3.69) | 0.94 (0.81 to 1.09) | 1.92 (1.21 to 3.05) | 2.21 (1.46 to 3.35) | 0.96 (0.79 to 1.16) | 2.13 (1.31 to 3.48) |
| p Value | <0.001 | 0.420 | 0.006 | <0.001 | 0.664 | 0.002 | |
*Participants were included under each relevant definition. Bronchodilators were not used. Cell counts unweighted; RRRs estimated using survey weights.
†FTs: obstruction (FT): FEV1/FVC <0.7. Diagnosed COPD: HSE: reported diagnosed chronic bronchitis, emphysema, or COPD; UKHLS: diagnosed bronchitis or emphysema.
‡LLN: obstruction (LLN): FEV1/FVC<LLN. Diagnosed COPD: HSE: reported diagnosed chronic bronchitis, emphysema, or COPD; UKHLS: diagnosed bronchitis or emphysema.
§The RRR is interpreted as the relative risk of one outcome in relation to the reference category for a specified category of an independent variable compared with the reference category for that independent variable. Using diagnosed alone as an example, the RRR for men versus women is interpreted as the relative risk for diagnosed alone versus neither diagnosed nor objective spirometry for men compared with the analogous relative risk for women, adjusted for the other variables in the model.
¶Reference category.
**Missing data: 12/7879 (0.2%) pack-years of cigarette smoking; 265/7879 (3.4%) NS-SEC.
COPD, chronic obstructive pulmonary disease; FEV1, maximum expiratory volume in 1 s; FTs, fixed thresholds; FVC, forced vital capacity; HSE, Health Survey for England; LLN, lower limit of normal (below the 5th centile of z-scores); NS-SEC, National Statistics Socio-Economic Classification; RRR; relative risk ratios; UKHLS, UK Household Longitudinal Survey.