TABLE 4

Incidence rates and hazard ratios of death and hospitalisations due to chronic obstructive pulmonary disease (COPD) by quartile (Q) of vital capacity % predicted

Q4#,¶Q3Q2Q1+p-value for trend
Subjects n172172173172
COPD events n (n per 1000person-years)22 (5.45)15 (3.92)23 (5.97)28 (8.16)
COPD events unadjusted hazard ratio (95% CI)1.000.76 (0.39–1.46)1.15 (0.64–2.07)1.64 (0.94–2.87)0.044
COPD events adjusted hazard ratio§ (95% CI)1.000.67 (0.35–1.31)1.03 (0.57–1.88)1.31 (0.74–2.32)0.183
Deaths unadjusted hazard ratio (95% CI)1.001.22 (0.98–1.50)1.24 (1.00–1.53)1.44 (1.16–1.78)0.001
Deaths adjusted hazard ratio§,ƒ (95% CI)1.001.05 (0.84–1.31)1.13 (0.91–1.40)1.26 (1.01–1.57)0.02
  • Q4: 109–139% predicted; Q3: 101–109% predicted; Q2: 93–101% predicted; Q1: 48–93% predicted. #: highest quartile; : reference quartile; +: lowest quartile; §: adjusted for smoking status (three groups: never, ex- and current smokers), diabetes, body mass index, height and physical activity (three groups: high, moderate and low physical activity); ƒ: additionally adjusted for systolic blood pressure and cholesterol.