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Here are the hypothetical results from three studies dealing with the effects of a hypothetical intervention on changes in resting systolic blood pressure. The study number is shown in column 1, the sample size in column 2, the intervention and control group treatment effect difference in column 3, and the 95% confidence interval in column 4. Using a random-effects model, the overall change in blood pressure for these three studies combined is approximately –3 mmHg, with a 95% confidence interval of –11 to 6 mmHg. These results are not significant because the interval crosses zero. The overall heterogeneity for this data was also not significant (Q = 0.39, p = 0.82).