Covariate | N studies | Coefficient (95% CI) | p value |
---|---|---|---|
Mean study age | 4 | 0.01 (−0.02, 0.03) | 0.432 |
Study age criteria (under 22 or over 18) | 4 | 0.36 (−1.06, 1.79) | 0.391 |
Type I or type II diabetes | 4 | 0.21 (−1.46, 1.89) | 0.640 |
Male (percent) | 4 | 0.001 (−0.035, 0.037) | 0.909 |
Study design | 4 | 0.40 (0.13, 0.66) | 0.022 |
Duration smoked | 3 | 0.003 (−0.063, 0.070) | 0.628 |