Equals 1 if female
Age in years divided by 100 (midpoint of 10 age groups)
AGE squared
Annual income in tens of thousands of dollars
Equals if private insurance
Equals 1 if free government insurance due to low income
Equals 1 if free government insurance due to old-age, disability or veteran stat
Number of illnesses in past 2 weeks
Number of days of reduced activity in past two weeks due to illness or injury
General health questionnaire score using Goldberg's method (High score bad hlth)
Equals 1 if chronic condition(s) but not limited in activity, 0 other
Equals 1 if chronic condition(s) and limited in activity, 0 otherwise
Number of doctor (or specialist) visits in past 2 weeks