Lung function at enrolment | p Value* | |||
Normal (N=1505) | Restrictive spirometric pattern (N=249) | Obstructive spirometric pattern (N=294) | ||
Mean±SD age (years) | 46±17 | 60±15 | 60±15 | NA |
Sex: % female | 56.3 | 67.1 | 46.9† ‡ | <0.001 |
Obesity: % with BMI ≥30 kg/m2 (n=1978) | 6.8 | 13.6† | 6.4‡ | 0.004 |
Years of formal education: % with >12 years | 45.8 | 37.8 | 32.0 | 0.27 |
Ever smoking: % with ≥ 1 pack-year (n=2046) | 53.9 | 50.6 | 77.1† ‡ | <0.001 |
Pack-years: geometric mean among ever smokers (n=1163) | 14.1 | 22.5 | 28.9† | 0.006 |
Physician-confirmed asthma: % positive (n=2046) | 8.2 | 14.1† | 23.5† ‡ | <0.001 |
Allergy skin tests: % positive (n=2012) | 39.7 | 25.9 | 31.6 | 0.28 |
Eosinophilia: % positive (n=1542) | 7.4 | 9.6 | 12.8† | 0.01 |
Total serum IgE in IU/ml: geometric mean (n=1836) | 27.5 | 21.5 | 37.8† ‡ | <0.001 |
Chronic cough and phlegm: % positive | 7.7 | 13.7† | 31.0† ‡ | <0.001 |
Shortness of breath with wheezing: % positive (n=2043) | 16.9 | 27.7† | 42.8† ‡ | <0.001 |
≥ Grade 2 on the modified MRC dyspnoea scale†: % positive (n=2038) | 9.5 | 24.0† | 34.9† ‡ | <0.001 |
Ever pneumonia: % positive | 23.0 | 40.6† | 39.5† | <0.001 |
Ever ‘heart trouble’: % positive | 13.8 | 26.1 | 20.7 | 0.36 |
Ever stroke: % positive | 1.1 | 6.0† | 3.1 | 0.05 |
Diabetes: % positive | 3.0 | 7.2 | 4.4 | 0.29 |
Deceased at January 2005: % deceased | 46.3 | 82.7 | 84.0 | NA |
N=2048 unless otherwise specified.
Statistical comparisons are completed across the three groups after adjustment for age (p value reported in the last column) as well as between pairs after adjustment for age and Bonferroni correction.
↵* p Value for the comparison across the three groups after adjustment for age.
↵† Significantly different from normal after adjustment for age and Bonferroni correction.
↵‡ Significantly different from restrictive spirometric pattern after adjustment for age and Bonferroni correction.