Assumptions and imputations used to calculate data if missing from published report
| Data needed | Data available | Assumptions/imputations |
|---|---|---|
| SD of the difference | SE of the difference | Multiply SE by square root of sample size |
| Confidence interval around the difference | For n ≥ 100, assume standard normal distribution For n < 100, assume t distribution | |
| SE of the difference | p value for mean difference | Convert p value to t value at same degrees of freedom; divide mean difference by t value |
| Final score | Baseline and change scores | Add or subtract the change score from baseline value |
| SD of final scores | SD of baseline and change scores | Sum baseline and change variances |
| SD | Range | No appropriate conversion possible |
Note: SD = standard deviation, SE = standard error.