title: Do professional interpreters improve clinical care for patients with limited English proficiency? A systematic review of the literature.
abstract: OBJECTIVE
  To determine if professional medical interpreters have a positive impact on clinical care for limited English proficiency (LEP) patients.
  
  
  METHODS
  A systematic literature search, limited to the English language, in PubMed and PsycINFO for publications between 1966 and September 2005, and a search of the Cochrane Library.
  
  
  METHODS
  Any peer-reviewed article which compared at least two language groups, and contained data about professional medical interpreters and addressed communication (errors and comprehension), utilization, clinical outcomes, or satisfaction were included. Of 3,698 references, 28 were found by multiple reviewers to meet inclusion criteria and, of these, 21 assessed professional interpreters separately from ad hoc interpreters. Data were abstracted from each article by two reviewers. Data were collected on the study design, size, comparison groups, analytic technique, interpreter training, and method of determining the participants' need for an interpreter. Each study was evaluated for the effect of interpreter use on four clinical topics that were most likely to either impact or reflect disparities in health and health care.
  
  
  RESULTS
  In all four areas examined, use of professional interpreters is associated with improved clinical care more than is use of ad hoc interpreters, and professional interpreters appear to raise the quality of clinical care for LEP patients to approach or equal that for patients without language barriers.
  
  
  CONCLUSIONS
  Published studies report positive benefits of professional interpreters on communication (errors and comprehension), utilization, clinical outcomes and satisfaction with care.
authors.affiliation: Division of General Internal Medicine, Medical Effectiveness Research Center for Diverse Populations, Department of Medicine, University of California, San Francisco, 1701 Divisadero, Suite 500, San Franicsco, CA 94143-1732, USA.
authors.forename: Leah S
authors.initials: LS
authors.lastname: Karliner
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Jacobs
authors.forename: Alice Hm
authors.initials: AH
authors.lastname: Chen
authors.forename: Sunita
authors.initials: S
authors.lastname: Mutha
mesh_terms: D003144:Communication Barriers; D006296:Health Services / Q000706:statistics & numerical data; D006297:Health Services Accessibility; D006302:Health Services Research / Q000458:organization & administration; D006801:Humans; D007802:Language; D017060:Patient Satisfaction; D010817:Physician-Patient Relations; D011787:Quality of Health Care / Q000191:economics / Q000458:organization & administration*; D014175:Translating; D016896:Treatment Outcome