| No over dispersion | Moderate overdispersion | High overdispersion | |||
---|---|---|---|---|---|---|
RaRa = 0.75 | RaRa = 0.77 | RaRa = 0.79 | ||||
 | Mean differenceb | SD | Mean difference | SD | Mean difference | SD |
Dichotomise RR | 0.15 | 0.07 | 0.14 | 0.08 | 0.14 | 0.08 |
Poisson RaR | <0.01 | 0.01 | <0.01 | 0.01 | <0.01 | 0.01 |
Simple RaR | <0.01 | 0.01 | <0.01 | 0.01 | <0.01 | 0.01 |
Time to the first event HR | 0.07 | 0.11 | 0.06 | 0.11 | 0.07 | 0.12 |
Marginal model HR | 0.02 | 0.09 | 0.01 | 0.09 | 0.01 | 0.10 |
Andersen-Gill HR | −0.01 | 0.08 | −0.02 | 0.09 | −0.02 | 0.09 |
Ratio of means | <0.01 | 0.03 | <0.01 | 0.04 | <0.01 | 0.04 |
Ratio of medians | 0.05 | 0.19 | 0.09 | 0.17 | 0.07 | 0.14 |