Advised missing data method

Longitudinal analysis > Missings in predictor/covariate > MAR > <10% missing data > <75% missing items

The imputation method should be applied to the the item scores in order to use the available item information. With this relatively small percentage of subjects with missing data, a stochastic regression imputation of the item scores may perform satisfactory. Even though, the missing data uncertainty is not incorporated in this method, in this situation where a small percentage of subjects have missing item scores(<10%), the effect of not including this uncertainty is negligible. Nevertheless, multiple imputation of the item scores would be more corect and can be applied in these situations as well.