Table 3 Meta-regression analysis for exploration of the sources of heterogeneity factors
Factors | Coefficient | Standard error | 95% CI | p value |
|---|---|---|---|---|
year | −0.12 | 0.20 | −3.06, 0.67 | 0.21 |
country | −1.19 | 0.95 | −2.99, 0.54 | 0.17 |
learners | 1.08 | 1.24 | −1.35, 3.52 | 0.38 |
course | −0.26 | 0.89 | −2.01, 1.49 | 0.77 |
intervention | −0.33 | 0.79 | −0.53, 0.27 | 0.67 |
comparator | 0.29 | 0.86 | −1.40, 1.99 | 0.73 |
duration | 0.09 | 0.95 | −1.77, 1.97 | 0.91 |