Subgroups | Sample size | No. of studies | Test of association# | Test of heterogeneity | Egger’s test for publication bias | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Online group | Offline group | OR (95% CI) | Z | Pvalue | Q | Pvalue | I 2(%) | t | Pvalue | ||
Overall effects | 17,580 | 10,853 | 14 | 1.35 (1.13, 1.62) | 3.28 | 0.001 | 93.06 | <0.001 | 86.0 | 0.16 | 0.880 |
European subsample | 10,718 | 5,141 | 6 | 1.38 (1.17, 1.63) | 3.84 | <0.001 | 14.88 | 0.011 | 66.4 | 0.82 | 0.457 |
American subsample | 4,181 | 4,866 | 5 | 1.21 (0.81, 1.82) | 0.93 | 0.354 | 49.60 | <0.001 | 91.9 | −0.57 | 0.606 |
Asian subsample | 2,681 | 846 | 3 | 1.63 (0.74, 3.62) | 1.20 | 0.229 | 28.20 | <0.001 | 92.9 | 1.37 | 0.402 |
Sample size > 500 | 16,984 | 10,205 | 11 | 1.32 (1.09, 1.61) | 2.79 | 0.005 | 85.48 | <0.001 | 88.3 | -0.09 | 0.930 |
Sample size ≤ 500 | 596 | 648 | 3 | 1.51(0.89, 2.56) | 1.52 | 0.128 | 7.40 | 0.025 | 73.0 | 2.62 | 0.232 |
UAI in the last 6 or more months | 9,564 | 6,557 | 6 | 1.28 (0.94, 1.76) | 1.56 | 0.12 | 62.11 | <0.001 | 92.0 | -0.79 | 0.850 |
UAI in the last 3 or less months | 8,016 | 4,296 | 8 | 1.40 (1.13, 1.74) | 3.03 | 0.002 | 30.44 | <0.001 | 77.0 | 1.11 | 0.645 |