Table 6.

Meta-analysis of postbronchodilator FEV₁/FVC ratio including interaction for age, diagnosis, atopy and steroid use

	Model 4
Variables	Estimates	Confidence limits (95%)		P value (estimate)*	I 2	P value (heterogeneity)†
Age/year from 20 years	−0.237	−0.270	−0.205	<0.001	34.1	0.083
Sex
Female	–	–	–	–	–	–
Male	−0.120	−0.963	0.723	0.780	0.0	0.724
Height/m	−0.090	−0.136	−0.044	<0.001	11.1	0.325
Cases grouping
Controls (ref)	–	–	–	–	–	–
Asthmatic (no atopy; limited/no steroid use)	3.227	−4.408	10.862	0.408	91.0	<0.001
Asthmatic (atopic; limited/no steroid use)	−0.645	−2.164	0.873	0.405	0.0	0.865
Asthmatic (no atopy; regular steroid use)	1.628	−6.628	9.883	0.699	79.2	<0.001
Asthmatic (atopic; regular steroid use)	−1.044	−4.561	2.473	0.561	67.9	<0.001
Sinusitis	−1.130	−3.796	1.537	0.406	51.7	0.009
Both Asthma & Sinusitis	−3.670	−10.319	2.978	0.279	87.3	<0.001
Age*case interaction
Controls (ref)	–	–	–	–	–	–
Asthmatic (no atopy; limited/no steroid use) *Age	−0.306	−0.548	−0.065	0.013	92.5	<0.001
Asthmatic(atopic; limited/no steroid use)*Age	−0.060	−0.114	−0.006	0.029	0.0	0.491
Asthmatic (no atopy; regular steroid use)*Age	−0.395	−0.835	0.045	0.078	98.4	<0.001
Asthmatic (atopic; regular steroid use)*Age	−0.243	−0.495	0.008	0.058	92.9	<0.001
Sinusitis *Age	0.026	−0.063	0.115	0.564	48.7	0.013
Both Asthma & Sinusitis*Age	0.007	−0.226	0.241	0.950	85.3	<0.001
Smoking (per pack year)	−0.085	−0.120	−0.050	<0.001	40.8	0.041
Smoking status
Never (ref)	–	–	–	–	–	–
Former	−0.429	−1.660	0.802	0.495	55.4	0.003
Current	−2.142	−3.154	−1.130	<0.001	0.0	0.621

Atopy was considered positive if ≥3 mm reaction size to any of the allergens.

FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity.

^*Effect Estimate.

†Heterogeneity of effects between centers.