Results of logistic and multinomial logistic regressions for reported 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§ | |||||
|---|---|---|---|---|---|---|---|
| Non-obstructed as reference | Non-obstructed as reference | ||||||
| Diagnosed-COPD† | Stage I | Stage II | Stage III+ | Stage I | Stage II | ||
| N | OR (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 | 0.60 (0.34 to 1.05) | 1.35 (1.16 to 1.58) | 1.35 (1.12 to 1.63) | 1.72 (1.08 to 2.76) | 1.07 (0.88 to 1.31) | 1.20 (0.96 to 1.50) |
| p Value | 0.075 | <0.001 | 0.002 | 0.024 | 0.503 | 0.107 | |
| Age group | |||||||
| 40–54** | 3416 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 55–64 | 2022 | 1.66 (1.07 to 2.58) | 2.00 (1.63 to 2.45) | 2.13 (1.65 to 2.73) | 6.05 (2.82 to 12.99) | 0.92 (0.72 to 1.18) | 1.57 (1.20 to 2.06) |
| 65–74 | 1451 | 0.96 (0.54 to 1.70) | 2.85 (2.30 to 3.53) | 3.01 (2.32 to 3.89) | 10.11 (4.55 to 22.49) | 0.83 (0.63 to 1.09) | 1.56 (1.16 to 2.12) |
| 75+ | 714 | 1.20 (0.39 to 3.70) | 4.72 (3.66 to 6.07) | 6.67 (5.00 to 8.90) | 22.26 (9.45 to 52.44) | 1.06 (0.74 to 1.51) | 2.20 (1.52 to 3.17) |
| p Value | 0.104 | <0.001 | <0.001 | <0.001 | 0.492 | <0.001 | |
| Pack-years†† | |||||||
| 0–0.9** | 4165 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| 1–19.9 | 1835 | 1.38 (0.88 to 2.17) | 1.61 (1.34 to 1.93) | 1.66 (1.29 to 2.15) | 3.82 (1.80 to 8.14) | 1.94 (1.51 to 2.49) | 2.22 (1.58 to 3.12) |
| 20–49.9 | 1269 | 2.91 (1.91 to 4.45) | 2.30 (1.86 to 2.85) | 4.56 (3.64 to 5.72) | 5.91 (2.81 to 12.45) | 3.39 (2.61 to 4.41) | 5.43 (3.98 to 7.41) |
| 50+ | 334 | 5.64 (3.45 to 9.22) | 2.34 (1.63 to 3.35) | 6.83 (4.85 to 9.63) | 17.27 (7.88 to 37.84) | 4.50 (2.96 to 6.84) | 11.20 (7.59 to 16.52) |
| 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 | 1.03 (0.68 to 1.58) | 1.18 (0.97 to 1.45) | 1.34 (1.04 to 1.72) | 1.01 (0.51 to 2.00) | 1.14 (0.88 to 1.48) | 1.35 (0.99 to 1.85) |
| Routine | 2701 | 1.61 (1.13 to 2.31) | 1.07 (0.89 to 1.29) | 1.82 (1.47 to 2.26) | 2.30 (1.36 to 3.88) | 1.28 (1.01 to 1.63) | 2.18 (1.67 to 2.85) |
| p Value | 0.012 | 0.246 | <0.001 | 0.002 | 0.123 | <0.001 | |
| Sample | |||||||
| UKHLS** | 5675 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| HSE | 1928 | 2.22 (1.60 to 3.07) | 0.95 (0.79 to 1.14) | 0.97 (0.79 to 1.20) | 0.99 (0.62 to 1.59) | 1.05 (0.82 to 1.33) | 0.99 (0.77 to 1.26) |
| p Value | <0.001 | 0.587 | 0.798 | 0.967 | 0.716 | 0.913 | |
| Males×age group | |||||||
| 40–54¶ | 1319 | 1.00 | – | – | – | – | – |
| 55–64 | 876 | 1.16 (0.54 to 2.45) | – | – | – | – | – |
| 65–74 | 664 | 3.21 (1.40 to 7.39) | – | – | – | – | – |
| 75+ | 372 | 2.61 (0.67 to 10.22) | – | – | – | – | – |
| p Value | 0.022 | – | – | – | – | – | |
*Participants were included under each relevant definition. Bronchodilators were not used. Cell counts are unweighted; ORs and RRRs estimated using survey weights.
†HSE: reported diagnosed COPD, bronchitis or emphysema; UKHLS: diagnosed bronchitis or emphysema.
‡FTs: stage I (FEV1/FVC <0.7 and FEV1 ≥80% of predicted); stage II (FEV1/FVC <0.7 and FEV1 50–79% of predicted); stage III+ (FEV1/FVC <0.7 and FEV1 <50% of predicted). Reference category: FEV1/FVC ≥0.7.
§LLN: stage I (FEV1/FVC<LLN and FEV1>LLN); stage II (FEV1/FVC<LLN and FEV1<LLN). Reference category: FEV1/FVC≥LLN.
¶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 FT stage I as an example, the RRR for men versus women is interpreted as the relative risk for FT stage I versus non-obstruction 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; OR, odds ratio; RRR; relative risk ratios; UKHLS, UK Household Longitudinal Survey.