Background: Patients are often transferred between hospitals to provide access to required specialty services. However, prior research suggests that transfer destinations are often chosen based on institutional relationships rather than solely on patient need. In this national study, we evaluated the appropriateness of transfer, as measured by the frequency of required specialty services available at the receiving hospital.Methods: We performed a retrospective analysis using 2013 100% Master Beneficiary Summary and Inpatient claims files from CMSmerged with 2013 American Hospital Association (AHA) data. Beneficiaries were eligible for inclusion if age ≥ 65, continuously enrolled in Medicare A and B, with an acute care hospitalization claim, excluding Medicare managed care and ESRD beneficiaries. We defined transferred patients as those with corresponding “transfer out” and “transfer in” claims, or either claim with corresponding hospital admission/discharge within 24 hours. We first identified primary diagnoses at time of transfer using ICD-9 codes, then identified those clearly requiring specialty services and the corresponding required services via expert opinion. We used McNemar’s test to compare the availability of each specialty service between receiving and transferring hospitals, stratified by diagnosis. If more than one specialty service corresponded to the diagnosis, we also compared the availability of at least one specialty service for that diagnosis.

Results: Of the 101,507 patients transferred to another hospital, 46,030 (45.3%) had a primary diagnosis decidedly requiring a specialty service (Table 1). For each diagnosis, availability of each corresponding specialty service, and of at least one specialty service, was more often present at the receiving compared to the transferring hospital (Table 2). However, depending on diagnosis, in 35-85% of transfers, services were just as available at the transferring hospital, and in 7-28% of transfers, the receiving hospitals did not have availability of any corresponding specialty service.

Conclusions: In our nationally representative evaluation of transferred patients, we found that patients requiring specialty services are transferred to hospitals more likely to have the appropriate services compared to the transferring hospital, implying appropriate transfer. However, notable exceptions to this rule were fairly frequent, suggesting potential other reasons for transfer in these instances, and warranting further investigation into hospital transfer practices and selection of transfer destination.