See the definition of variable STR_HIST1_AGE.

TROMSO_STR_HIST1_AGE

Name: STR_HIST1_AGE

Short description: Age of documented stroke diagnosis

Type: Decimal

Description and values:

Age (in years) at which the subject was diagnosed with documented stroke 

If information is missing then code 9999.

Local variable explanation:

datoslag= date of documented stroke

fdato=date of birth

SAS code:

If STR_HIST1 EQ 1 then STR_HIST1_AGE=(datoslag-fdato)/365.25;

else STR_HIST1_AGE=9999;