Interpreter services and effect on healthcare - a systematic review of the impact of different types of interpreters on patient outcome

BACKGROUND: Utilization of interpreters to facilitate communication between health care providers and non-native speaking patients is essential to provide the best possible quality of care. Yet use and policy on the subject vary widely, as does knowledge on the effect of different types of interpreters. This paper systematically reviews the literature on use of interpreters in the medical setting to evaluate their effects on the quality of care. MATERIAL AND METHODS: We conducted a literature search of PubMed and Embase, supplemented with references from relevant previous literature. We included any report in a medical setting comparing one type of interpretation to any other, including no interpretation and measuring a patient outcome. No limit was set on time or language. Risk of bias was assessed using the Evidence Project Risk of Bias assessment tool and the CASP checklist for qualitative studies. Results were synthesized using REDCap and presented in tables. RESULTS: We identified 29 reports represented by five types of studies. Types of interpreter intervention examined were professional, ad hoc, relational, any and no interpreter. Outcomes measured were satisfaction, communication, utilization and clinical outcomes. Results were indicative of in-person professional interpreter resulting in highest satisfaction and communication, reaffirming that any interpreter is better than none and relational interpreters can be a valuable interpreter resource for patients in the private practice setting. To be able to further differentiate on outcome for interventions of ad-hoc or relational interpreters, further data is needed. DISCUSSION: In-person Professional interpreter is the interpreter type resulting in greatest satisfaction and best communication outcome for the patients. This review is limited by most data originating from one country, interpretation from mainly Spanish to English and in one cultural setting. FUNDING: No funding was provided for this review.