title: HMO enrollment and Medicaid. Survival analysis with a Weibull function.
abstract: This paper analyzes the length of enrollment in Health Maintenance Organizations (HMOs) by performing secondary data analysis. It estimates a Weibull survival function using only simple regression. For middle-class enrollees in one HMO, the hazard rate (the disenrollment rate for the remaining members of a cohort) falls sharply with the length of enrollment. For medicaid beneficiaries allowed to remain in the fee-for-service sector, the hazard rate in another HMO is much greater but falls less sharply. Limiting the choice of Medicaid beneficiaries to HMOs would increase their length of enrollment, lowering a major barrier to HMOs' participation in Medicaid.
authors.affiliation: Urban Institute, Washington, DC 20037.
authors.forename: W P
authors.initials: WP
authors.lastname: Welch
mesh_terms: D004812:Epidemiologic Methods; D006279:Health Maintenance Organizations; D006801:Humans; D008484:Medicaid; D013223:Statistics as Topic; D013997:Time Factors; D014481:United States