Inpatient psychiatric care of Medicare beneficiaries with state buy-in coverage.

Administrative data were used to compare length of stay, Medicare payment, total and average daily costs, discharge destinations, rehospitalizations, and emergency room (ER) use of dually eligible and non-dually eligible Medicare inpatients admitted for a psychiatric diagnosis. Regressions controlled for State buy-in coverage as a proxy for dual eligibility, hospital type, and beneficiary sociodemographic and clinical characteristics. Measures of severity within diagnostic category were limited to comorbidities. Among disabled beneficiaries, dually eligible beneficiaries had lower costs and shorter stays. Among elderly and disabled persons, dually eligible beneficiaries had higher rates of rehospitalization, post-discharge ER use without admission, and discharge to destinations other than self-care.