Impact of interpreter services on delivery of health care to limited-English-proficient patients

Abstract
OBJECTIVE: To determine whether professional interpreter services increase the delivery of health care to limited-English-proficient patients. DESIGN: Two-year retrospective cohort study during which professional interpreter services for Portuguese and Spanish-speaking patients were instituted between years one and two. Preventive and clinical service information was extracted from computerized medical records. SETTING: A large HMO in New England. PARTICIPANTS: A total of 4,380 adults continuously enrolled in a staff model health maintenance organization for the two years of the study, who either used the comprehensive interpreter services (interpreter service group [ISG]; N=327) or were randomly selected into a 10% comparison group of all other eligible adults (comparison group [CG]; N=4,053). MEASUREMENTS AND MAIN RESULTS: The measures were change in receipt of clinical services and preventive service use. Clinical service use and receipt of preventive services increased in both groups from year one to year two. Clinical service use increased significantly in the ISG compared to the CG for office visits (1.80 vs 0.70; P<.01), prescriptions written (1.76 vs 0.53; P<.01), and prescriptions filled (2.33 vs 0.86; P<.01). Rectal examinations increased significantly more in the ISG compared to the CG (0.26 vs 0.02; P=.05) and disparities in rates of fecal occult blood testing, rectal exams, and flu immunization between Portuguese and Spanish-speaking patients and a comparison group were significantly reduced after the implementation of professional interpreter services. CONCLUSION: Professional interpreter services can increase delivery of health care to limited-English-speaking patients.