Enduring enrolments in West Virginia's Medicaid programme due to severe injury.

OBJECTIVE: To assess frequency, duration and costs of Medicaid conversions that occur when severe injury causes patients to enrol in Medicaid to pay their hospital bills. Once enrolled, Medicaid pays all their medical bills, not simply their injury bill.

DATA SOURCES: 2000-2005 West Virginia Medicaid claims data and 2000-2006 eligibility data for new enrollees under the age of 65. To model national costs, published Medicaid conversion rates across 14 states for 2003 and 2008 Healthcare Cost and Utilization Program Nationwide Inpatient Sample data.

METHODS: We identified enrollees who had hospital inpatient claims for injury within 30 days of enrolment, then tabulated eligibility duration and payments by year and in aggregate. For those with open-ended eligibility, we assumed future annual claims payments would equal average payments in eligibility years 5-6. We multiplied the mean payments data adjusted to national prices with the estimated conversions nationally.

RESULTS: Overall, 5.4% of hospitalised patients with injury in West Virginia converted to Medicaid, with 17% of conversions on Medicaid 7 years post injury. In 2010 dollars, Medicaid payments averaged $93 900 per conversion for non-injury medical care before the age of 65. Conversions added an estimated $87 in payments for non-injury care to governments' medical payments per medically treated injury in the USA. They added 14% to governments' gunshot and assault medical payments, 7.5% to its road crash medical payments and 6% to its total injury medical payments.

CONCLUSIONS: These findings increase the rationale for governments to partner in injury prevention efforts.