Table 2.
Subgrouping variable | Number of studies | Pooled estimate | 95% Confidence interval | tau‐squared | p Value |
---|---|---|---|---|---|
Continent | |||||
Europe | 29 | 7.76 | 4.35–13.45 | 2.82 | p = 0.90 |
North America | 11 | 6.09 | 3.75–9.73 | 0.73 | |
Asia | 11 | 5.84 | 2.98–11.13 | 1.39 | |
Australia | 2 | 6.28 | 3.74–10.37 | 0.11 |