Examining effectiveness of medical interpreters in emergency departments for Spanish-speaking patients with limited English proficiency: results of a randomized controlled trial.

STUDY OBJECTIVES This study examines whether availability of in-person professional interpreter services during emergency department (ED) visits affects satisfaction of limited English proficient patients and their health providers, using a randomized controlled trial. METHODS We randomized time blocks during which in-person professional interpreters were available to Spanish-speaking patients in the EDs of 2 central New Jersey hospitals. We assessed the intervention's effects on patient and provider satisfaction through a multilevel regression model that accounted for the nesting of patients within time blocks and controlled for the patient's age and sex, hospital, and when the visit occurred (weekday or weekend). RESULTS During the 7-month intake period, 242 patients were enrolled during 101 treatment time blocks and 205 patients were enrolled during 100 control time blocks. Regression-adjusted results indicate that 96% of treatment group patients were "very satisfied" (on a 5-point Likert scale) with their ability to communicate during the visit compared with 24% of control group patients (odds ratio=72; 95% confidence interval 31 to 167). (Among control group members who were not very satisfied, responses ranged from "very dissatisfied" to "somewhat satisfied.") Similarly, physicians, triage nurses, and discharge nurses were more likely to be very satisfied with communication during treatment time blocks than during control time blocks. We did not assess acuity of illness or global measures of satisfaction. CONCLUSION Use of in-person, professionally trained medical interpreters significantly increases Spanish-speaking limited English proficient patients' and their health providers' satisfaction with communication during ED visits.