Anaemia is associated with COPD morbidity
Anaemia | Polycythaemia | |||
β (95% CI)# | p-value | β (95% CI)# | p-value | |
CAT score | 1.40 (0.40–2.41) | 0.006 | −0.31 (−1.80–1.19) | 0.69 |
mMRC dyspnoea score | 0.28 (0.12–0.44) | 0.001 | 0.07 (−0.16–0.31) | 0.55 |
SGRQ score | 4.19 (1.86–6.51) | <0.001 | 0.49 (−2.95–3.94) | 0.78 |
SF-36 general | −2.14 (−3.47– −0.81) | 0.002 | 1.24 (−0.73–3.21) | 0.22 |
SF-36 physical function | −2.80 (−4.13 – −1.48) | <0.001 | 0.40 (−1.57–2.37) | 0.69 |
SF-36 mental health | −1.47 (−2.92– −0.01) | 0.048 | −0.37 (−2.52–1.79) | 0.74 |
6MWD m | −51.0 (−65.4– −36.6) | <0.001 | −0.2 (−21.4–20.9) | 0.98 |
Moderate exacerbations# | 1.06 (0.76–1.49) | 0.72 | 0.71 (0.41–1.24) | 0.23 |
Severe exacerbations# | 1.63 (1.10–2.40) | 0.01 | 1.24 (0.64–2.38) | 0.52 |
Models adjusted for age, sex, ethnicity, education, body mass index, pack-years smoking, smoking status, congestive heart failure, hypertension, diabetes mellitus, chronic kidney disease, % emphysema, forced expiratory volume in 1 s % predicted, and diffusing capacity of the lung for carbon monoxide % predicted. Coefficients and p-values are in comparison to normal haemoglobin. β coefficient units are points for CAT, mMRC, SGRQ, and SF-36 scores, and metres for 6MWD. CAT: COPD Assessment Test; mMRC: modified Medical Research Council Dyspnoea Score; SGRQ: St. George's Respiratory Questionnaire; SF-36: Medical Outcomes Study Short Form 36-item Questionnaire; 6MWD: 6-min walk distance. #: RR (95% CI) for moderate and severe exacerbations.