TABLE 3.
Heterogeneity | Effect of Region | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Disorder | Regiona | N of studies | OR | 95% CI lower | 95% CI upper | p Value | Qdf Within | p Value | Variance explained, % | Qdf Between | p Value |
Mood disorder | Asia | 4 | 28.61 | 14.91 | 54.92 | <.001 | 8.33 | .04 | 64 | 9.603 | .022b |
Australia/Oceania | 3 | 6.90 | 3.50 | 13.61 | <.001 | 5.332 | .07 | 62 | |||
Europe | 6 | 10.62 | 4.50 | 25.09 | <.001 | 25.135 | <.001 | 80 | |||
North America | 5 | 17.32 | 9.42 | 31.85 | <.001 | 3.794 | .44 | 0 | |||
Major depressionc | Asia | 6 | 26.87 | 15.58 | 46.36 | <.001 | 2.35 | .80 | 0 | 7.632 | .022d |
Europe | 4 | 7.95 | 3.30 | 19.16 | <.001 | 14.53 | .002 | 79 | |||
North America | 6 | 7.68 | 2.60 | 22.70 | <.001 | 21.05 | .001 | 76 | |||
Substance use disorder | Asia | 4 | 3.35 | 2.00 | 5.61 | <.001 | 2.682 | .26 | 25 | 4.983 | .173 |
Australia/Oceania | 3 | 2.64 | 1.35 | 5.14 | .004 | 6.762 | .03 | 70 | |||
Europe | 7 | 6.54 | 3.76 | 11.39 | <.001 | 16.226 | .01 | 63 | |||
North America | 5 | 3.97 | 1.99 | 7.90 | <.001 | 5.484 | .24 | 27 |
OR, odds ratio; CI, confidence interval; df, degrees of freedom.
Random effects model used to combine studies within each region.
Pairwise comparisons: Asia vs. Australia/Oceania, Q1 = 8.77, p = .003; Asia vs. Europe, Q1 = 3.24, p = .072; Asia vs. North America, Q1 = 1.22, p = .270; Australia/Oceania vs. Europe, Q1 = 0.60, p = .44; Australia/Oceania vs. North America, Q1 = 3.91, p = .048; Europe vs. North America, Q1 = 0.83, p = .36.
Australia/Oceania and Central America were excluded from analyses because there were <3 studies within each region.
Pairwise comparisons: Asia vs. Europe, Q1 = 5.32, p = .021; Asia vs. North America, Q1 = 4.09, p = .043; Europe vs. North America, Q1 = 0.00, p = .96.