TABLE 4

Change of lung function and prevalence of hospital/emergency room (ER) admissions for breathing problems over follow-up

HealthyAsthma aloneACOSCOPD aloneOverall p-value#
Subjects5659941218166
FEV1 change mL·year−1−26.2 (−31.1– −21.3)−25.3 (−30.5– −20.1)−25.9 (−32.2– −19.6)−37.3 (−44.0– −30.6)***<0.001
FEV1 change % of baseline·year−1−0.69 (−0.83– −0.55)−0.68 (−0.83– −0.53)−0.66 (−0.84– −0.47)−1.17 (−1.37– −0.97)***<0.001
FVC change mL·year−1−19.8 (−25.6– −14.1)−21.3 (−27.4– −15.2)−25.5 (−33.0– −18.0)*−37.0 (−45.0– −29.0)***<0.001
FVC change % of baseline·year−1−0.42 (−0.55– −0.29)−0.45 (−0.59– −0.31)−0.55 (−0.72– −0.38)*−0.81 (−0.99– −0.63)***<0.001
Hospital/ER admission for  breathing problems %3.6 (2.7–4.5)11.9 (8.7–15.0)***15.8 (9.9–21.8)***8.1 (3.5–12.7)**<0.001
  • Data are presented as n or mean (95% CI), unless otherwise stated. Change of lung function was adjusted using linear regression models, with forced expiratory volume in 1 s (FEV1) or forced vital capacity (FVC) change as dependent variables, sex, age, height and disease status as independent variables, and a random intercept term for European Community Respiratory Health Survey (ECRHS) centre and sample. A negative value represents lung function decline. Prevalence of hospital admissions for breathing problems was adjusted using a logistic regression model, with hospital/ER admissions as dependent variables, sex, age and disease status as independent variables, and a random intercept term for ECRHS centre and sample. ACOS: asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome; AHR: airway hyperresponsiveness. #: refers to the comparison across the groups; : present if a subject answered positively to one or both of “Since the last survey, have you spent a night in hospital?” or “Have you visited a hospital casualty department or ER because of breathing problems?” *: p<0.05; **: p<0.01; ***: p<0.001 for the comparison of the disease group with the “healthy” category.