PATIENT-SPECIFIC PREDICTORS OF AMBULANCE USE

Study objective: To determine patient-specific socioeconomic and healt h status characteristics for patients arriving by ambulance at an emer gency department. Methods: Ambulance use among adult ED patients prese nting with abdominal pain, chest pain, head trauma, or shortness of br eath was studied at five urban leaching hospitals in the northeastern United States. Cross-sectional analysis within a prospective cohort st udy of 4,979 consecutive patients was performed using an interval sequ ence subset of 2,315 patients (84% of those eligible) to whom question naires were administered. Ambulance use (21% of surveyed patients; 26% of all patients) was analyzed with logistic regression. Results: Pred ictors of ambulance use included age greater than 65 years (odds ratio [OR], 1.95; 95% confidence interval [CI], 1.34 to 2.82); clinical sev erity (OR, 3.11; 95% CI, 2.27 to 4.25); poverty (OR, 1.40; 95% CI, 1.0 8 to 1.83); physical function (OR, 1.05; 95% CI, 1.02 to 1.09 for each point of worsening function on a 12-point physical function scale); a nd various types of health insurance coverage. Race, sex, education, M edicaid coverage, frequency of ED use, living arrangements, and primar y physician availability were not predictive in multivariate analysis of surveyed patients. Conclusion: Ambulance use varies by age, clinica l severity, income, patient-specific characteristics of physical funct ion, and type of health insurance. Medicaid coverage and frequent ED u se are not predictive of increased ambulance use.