A National Study of Outpatient Health Care Providers' Effect on Emergency Department Visit Acuity and Likelihood of Hospitalization.

STUDY OBJECTIVE: Many policymakers believe that expanding access to outpatient care will reduce emergency department (ED) use. However, outpatient health care providers often refer their patients to EDs for evaluation and management. We examine the factors underlying outpatient provider referral, its effect on ED visit volume, and whether referred ED visits are more likely to result in hospitalization than self-referred visits.

METHODS: We conducted a cross-sectional study of 19,342 adult (>18 years) respondents to the 2012 to 2014 National Health Interview Survey who reported they had visited an ED at least once in the past 12 months, representing an estimated 44,152,870 US adults. We categorized individuals as having been referred to the ED by an outside health care provider if they responded affirmatively to "your health care provider advised you to go" as a reason for their most recent ED visit. We performed descriptive analyses and logistic regressions to examine factors associated with outpatient health care provider referral to the ED. Respondents could choose multiple other reasons for their most recent ED visit, and we used existing Centers for Disease Control and Prevention guidelines to group these reasons into 2 categories: seriousness of the medical condition and lack of access to other providers. Our 2 main outcomes were whether an outpatient health care provider referred an individual to the ED and whether that ED visit resulted in hospitalization.

RESULTS: Of the 44,152,870 US adults (18.58%; 95% confidence interval [CI] 18.21% to 18.95%) with one or more ED visits in the previous 12 months, 10,913,271 (24.72%; 95% CI 23.80% to 25.64%) were referred to the ED by an outpatient provider. Respondents who reported their ED visit was due to the seriousness of their medical condition were more likely to be referred to the ED (odds ratio [OR] 2.18; 95% CI 1.91 to 2.49), whereas those reporting a lack of access to other providers were less likely to be referred (OR 0.58; 95% CI 0.52 to 0.64). Visits referred to the ED were more likely to result in hospitalization than self-referrals (OR 2.07; 95% CI 1.87 to 2.31).

CONCLUSION: Almost one quarter of individuals' most recent ED visits were driven by referrals from outpatient health care providers. Being referred to the ED by an outpatient provider is strongly associated with the seriousness of one's medical condition, which also increases the odds of hospitalization compared with ED discharge. After controlling for seriousness of medical condition, ED referral by an outpatient provider continues to have an independent association with hospitalization.