Prevalence of chronic illness in HMOs and indemnity plans.
D002908:Chronic Disease / Q000453:epidemiology*; D003625:Data Collection; D018588:Fee-for-Service Plans / Q000706:statistics & numerical data*; D006279:Health Maintenance Organizations / Q000706:statistics & numerical data*; D006304:Health Status; D006801:Humans; D015995:Prevalence; D014481:United States / Q000453:epidemiology