Table 5.
Meta-analysis of postbronchodilator FEV1/FVC ratio including interaction for age, diagnosis and steroid use
| Model 3 |
||||||
|---|---|---|---|---|---|---|
| Variables | Estimates | Confidence limits (95%) | P value* | I 2 | P value (heterogeneity)† | |
| Age/year from 20(years) | −0.239 | −0.272 | −0.206 | <0.001 | 36.4 | 0.067 |
| Sex | ||||||
| Female | – | – | – | – | – | – |
| Male | −0.127 | −0.961 | 0.707 | 0.765 | 0.0 | 0.659 |
| Height/m | −0.091 | −0.135 | −0.046 | <0.001 | 8.4 | 0.356 |
| Cases grouping | ||||||
| Controls (ref) | – | – | – | – | – | – |
| Asthmatic (limited/no steroid use) | −0.281 | −1.753 | 1.191 | 0.708 | 0.0 | 0.930 |
| Asthmatic (regular steroid use) | −0.048 | −3.476 | 3.380 | 0.978 | 56.5 | 0.004 |
| Sinusitis | −1.180 | −3.886 | 1.526 | 0.393 | 54.1 | 0.005 |
| Both Asthma & Sinusitis | −3.622 | −10.181 | 2.936 | 0.279 | 87.3 | <0.001 |
| Age*case interaction | ||||||
| Controls (ref) | – | – | – | – | – | – |
| Asthmatic (limited/no steroid use) *Age | −0.150 | −0.267 | −0.033 | 0.012 | 75.4 | <0.001 |
| Asthmatic (regular steroid use) *Age | −0.281 | −0.485 | −0.076 | 0.007 | 85.5 | <0.001 |
| Sinusitis*Age | 0.028 | −0.062 | 0.117 | 0.545 | 50.5 | 0.009 |
| Both Asthma & Sinusitis*Age | 0.006 | −0.224 | 0.237 | 0.958 | 85.3 | <0.001 |
| Smoking (per pack year) | −0.084 | −0.120 | −0.049 | <0.001 | 39.0 | 0.051 |
| Smoking status | ||||||
| Never (ref) | – | – | – | – | – | – |
| Former | −0.479 | −1.716 | 0.759 | 0.449 | 56.9 | 0.002 |
| Current | −2.261 | −3.269 | −1.253 | <0.001 | 0.0 | 0.629 |
Regular steroid users were those who reported use of steroid inhalers for at least two and half years over the last five years. FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.
*
Effect Estimate.
†
Heterogeneity of effects between centers.