[EpiData-list] Help with calculation using fields from 2 files

Dear fellow EpiData users,

I have 2 data files, a demographics file called demo.rec and an assessment file called assess.rec. Demo.rec contains date of birth while assess.rec contains date of assessment. I'd like to calculate the age at assessment and display the age in assess.rec during data entry. How can I do a calculation using fields in 2 different files?

An abbreviated version of my files with just the relevant fields are: demo.qes idno ### dob <dd/mm/yyyy> gender #

demo.chk idno KEY UNIQUE 1 END

gender LEGAL 1 2 END AFTER ENTRY RELATE idno assess END END

assess.qes idno ### dateass <dd/mm/yyyy> ageass ##.#

assess.chk idno KEY 1 END

dateass AFTER ENTRY LET ageass=(dateass-???)/365.25 END END

ageass NOENTER END

Any help would be greatly appreciated.

Thanks, Suzanna

Suzanna Vidmar Senior Research Officer

Clinical Epidemiology and Biostatistics Unit Royal Children's Hospital Flemington Rd Parkville Victoria 3052

telephone: +61 3 9345 6372 facsimile: +61 3 9345 6000