Background: In the United States, the Emergency Medical Treatment and Active Labor Act defines broad guidelines regarding interhospital transfer of patients who have sought care in the emergency department. However, patient transfers for nonmedical reasons are still considered a common practice. The purpose of this study was to evaluate the possible risk factors for hospital transfer in a population of patients unlikely to require transfer to a level-I center for medical reasons.

Methods: A retrospective case-control national database study was performed with use of data from the National Trauma Data Bank (version 4.3). The study group consisted of patients with low Injury Severity Scores (=9) who were transferred to a level-I trauma center from another hospital. The controls were patients with low Injury Severity Scores who were treated at any hospital that was lower than a level-I trauma center and were not transferred. Hypothesized risk factors for hospital transfer were the age, gender, race, and insurance status of the patient; the time of day the transfer was received; and the number and type of comorbidities.

Results: The total sample included 97,393 patients, 21% of whom were transferred to a level-I trauma center. The odds ratios adjusted for all risk factors indicated that transfer rates were higher for male patients compared with female patients (adjusted odds ratio = 1.46), children compared with seniors (3.54), blacks compared with whites (1.28), evening or night transfers compared with morning or afternoon transfers (2.25), patients with Medicaid compared with those with other types of insurance (2.02), and for those with one or more comorbidities compared with those with no comorbidity (2.79).

Conclusions: These results suggest the need for prospective studies to further investigate the relationships between hospital transfer and medical and nonmedical factors.

Level of Evidence: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.