Missing data in a long food frequency questionnaire: are imputed zeroes correct?
Although some missing data represent true zeroes, much of it does not, and data are usually not missing at random. Automatic imputation of zeroes for missing data will usually be incorrect, although there is [corrected] little bias unless the foods are frequently consumed. Certain identifiable subgroups have greater amounts of missing data, and require greater care in making imputations.
The RACP's Statement on routine male circumcision is not evidence-based and should be retracted.