Avon Longitudinal Study of Parents and Children
ALSPAC Adolescence (13 years – 18 years 11 months)
Codes
Name
TC3000
-
-9999 
Consent withdrawn -
-11 Triplet / quadruplet -
-10 Not completed -
-1 No response -
1 Under 30 mins -
2 30 mins - 1 hour -
3 1-2 hours -
4 2-4 hours -
5 4-6 hours -
6 Over 6 hours -
7 Never