[EpiData-list] adding variables to existing rec. file

Can anyone give me advice on how to add a variable to an existing rec file when data entry during an ongoing cohort study without loosing the recorded data entries? Thanks Philipp

Dr. Philipp Zanger, MD DTM DEpi Internist / Tropenmedizin Institut für Tropenmedizin Wilhelmstraße 27 72074 Tübingen Tel.: 0049-(0)7071-29-82365 Fax: 0049-(0)7071-29-5267