Impact of patient language proficiency and interpreter service use on the quality of psychiatric care: a systematic review.

OBJECTIVE: This literature review examined the effects of patients' limited English proficiency and use of professional and ad hoc interpreters on the quality of psychiatric care.
METHODS: PubMed, PsycINFO, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) were systematically searched for English-language publications from inception of each database to April 2009. Reference lists were reviewed, and expert sources were consulted. Among the 321 articles identified, 26 met inclusion criteria: peer-reviewed articles reporting primary data on clinical care for psychiatric disorders among patients with limited proficiency in English or in the provider's language.
RESULTS: Evaluation in a patient's nonprimary language can lead to incomplete or distorted mental status assessment. Although both untrained and trained interpreters may make errors, untrained interpreters' errors may have greater clinical impact, compromising diagnostic accuracy and clinicians' detection of disordered thought or delusional content. Use of professional interpreters may improve disclosure in patient-provider communications, referral to specialty care, and patient satisfaction.
CONCLUSIONS: Little systematic research has addressed the impact of language proficiency or interpreter use on the quality of psychiatric care in contemporary U.S. settings. Findings are insufficient to inform evidence-based guidelines for improving quality of care among patients with limited English proficiency. Clinicians should be aware of the ways in which quality of care can be compromised when they evaluate patients in a nonprimary language or use an interpreter. Given U.S. demographic trends, future research should help guide practice and policy by addressing deficits in the evidence base.