Table 2.
Subgroup | Number of studies | Pooled RR | 95% CI | Heterogeneity |
---|---|---|---|---|
AllSample size | 6 | 1.02 | 0.93–1.11 | P = 0.18; I2 = 33% |
<30,000 | 2 | 0.91 | 0.72–1.14 | P = 0.20; I2 = 38% |
>30,000 | 4 | 1.04 | 0.94–1.14 | P = 0.18; I2 = 36% |
Gender | ||||
Male | 2 | 0.95 | 0.81–1.11 | P = 0.74; I2 = 0% |
Female | 3 | 1.09 | 0.90–1.32 | P = 0.12; I2 = 54% |
Location | ||||
USA | 4 | 1.00 | 0.84–1.18 | P = 0.05; I2 = 62% |
Other | 2 | 1.00 | 0.82–1.20 | P = 0.61; I2 =0% |
Adjustment of cigarette smoking | ||||
Adjusted | 4 | 1.04 | 0.94–1.14 | P = 0.18; I2 = 36% |
Unadjusted | 2 | 0.91 | 0.72–1.14 | P = 0.20; I2 = 38% |
Adjustment of physical activity | ||||
Adjusted | 3 | 1.04 | 0.88–1.22 | P = 0.07; I2 = 62% |
Unadjusted | 3 | 0.95 | 0.80–1.13 | P = 0.41; I2 = 0% |
Adjustment of hypertension | ||||
Adjusted | 2 | 0.95 | 0.84–1.08 | P = 0.93; I2 = 0% |
Unadjusted | 4 | 1.08 | 0.96–1.22 | P = 0.13; I2 = 43% |