[R-meta] including uninformative levels
Dear C?tia In general, in regression, if you have a level in one of the factors which is represented by a single observation then that observation will be perfectly fitted and that observation will have high leverage. In a random-effects model since it should contribute to the between study variation then it would affect all the estimates since the weights are dependent on the estimate of tau^2. Michael
On 03/12/2021 13:29, C?tia Ferreira De Oliveira wrote:
Hello, I hope you are well. Is there any benefit/disadvantage of including levels in your model that only have information coming from a single study? I always remove the intercept and do not include it in the follow-up comparisons between levels but wonder if there's a consequence to doing it this way since this one study will potentially introduce more heterogeneity and does not add much empirical value for this particular analysis. Best wishes, Catia