What does it mean if, e.g. in the MMSE.csv file, there are two entries with the same RID & same EXAMDATE, but different USERDATE/VISCODE columns? Does it mean this data was not collected at the second visit, and so the data collected at the first visit was entered for both visits?
These appear to be erroneous repeat entries. Our recommendation is to use the records with the exam dates that are more consistent with the visit code and remove the other record with the same exam date.
These appear to be erroneous repeat entries. Our recommendation is to use the records with the exam dates that are more consistent with the visit code and remove the other record with the same exam date.