Assessment of trust in physician: a systematic review of measures.

Over the last decades, trust in physician has gained in importance. Studies have shown that trust in physician is associated with positive health behaviors in patients. However, the validity of empirical findings fundamentally depends on the quality of the measures in use. Our aim was to provide an overview of trust in physician measures and to evaluate the methodological quality of the psychometric studies and the quality of psychometric properties of identified measures. We conducted an electronic search in three databases (Medline, EMBASE and PsycInfo). The secondary search strategy included reference and citation tracking of included full texts and consultation of experts in the field. Retrieved records were screened independently by two reviewers. Full texts that reported on testing of psychometric properties of trust in physician measures were included in the review. Study characteristics and psychometric properties were extracted. We evaluated the quality of design, methods and reporting of studies with the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was assessed with Terwee's 2007 quality criteria. After screening 3284 records and assessing 169 full texts for eligibility, fourteen studies on seven trust in physician measures were included. Most of the studies were conducted in the USA and used English measures. All but one measure were generic. Sample sizes range from 25 to 1199 participants, recruited in very heterogeneous settings. Quality assessments revealed several flaws in the methodological quality of studies. COSMIN scores were mainly fair or poor. The overall quality of measures' psychometric properties was intermediate. Several trust in physician measures have been developed over the last years, but further psychometric evaluation of these measures is strongly recommended. The methodological quality of psychometric property studies could be improved by adhering to quality criteria like the COSMIN checklist.