Table 3.
Meta-regression analysis coefficients of risk ratio and prevalence of COPD
| Variables | Coefficient (SE) | 95% CI | t | P |
|---|---|---|---|---|
| Risk ratio | ||||
| Publication year | −0.0772 (0.0179) | [− 0.1270,-0.0275] | −4.31 | 0.013 |
| Age of cases | −0.0387(0.0185) | [− 0.0975, 0.0201] | −2.10 | 0.127 |
| N of cases | < 0.0001(< 0.0001) | [< −0.0001, 0.0002] | 0.87 | 0.450 |
| N of controls | < 0.0001(< 0.0001) | [< −0.0001, < 0.0001] | 1.83 | 0.164 |
| N of participants | < 0.0001(< 0.0001) | [< −0.0001, < 0.0001] | 1.78 | 0.174 |
| Female proportion | 0.0025(0.0019) | [−0.0037, 0.0086] | 1.28 | 0.290 |
| Follow up duration | −0.0112 (0.0066) | [−0.0320, 0.0097] | −1.70 | 0.187 |
| Quality | −0.2916 (0.1396) | [−0.6793, 0.0962] | −2.09 | 0.105 |
| Beginning of cohort | −0.0085 (0.0053) | [−0.0232, 0.0062] | −1.61 | 0.182 |
| Duration of cohort | 0.0073 (0.058) | [−.0088, 0.0233] | 1.25 | 0.278 |
| Prevalence | ||||
| Publication year | 0.0045 (0.0040) | [−0.0052, 0.0143] | 1.14 | 0.296 |
| Number of cases | < 0.0001(< 0.0001) | [< −0.0001, < 0.0001] | 1.42 | 0.206 |
| Age of cases | −0.0011 (0.0036) | [−0.0099, 0.0078] | − 0.30 | 0.777 |
| Female proportion | −0.0015 (0.0011) | [−0.0042, 0.0012] | −1.36 | 0.221 |
| Smoker proportion | 0.0031 (0.0006) | [0.0012, 0.0049] | 5.33 | 0.013 |
| Disease duration | 0.0005 (0.0004) | [−0.0008, 0.0019] | 1.32 | 0.239 |
| Quality | −0.0015 (0.0071) | [−0.0188, 0.0159] | − 0.21 | 0.844 |
CI: confidence interval; N: number; SE: standard error