A decade of studying implicit racial/ethnic bias in healthcare providers using the implicit association test

Introduction

Existing research indicates that Black, Indigenous, and people of color have worse health outcomes than white people, including incidence, prevalence, severity of disease at diagnosis, rates of mortality, and lower quality of care, despite efforts to close these gaps. The health disparity gap begins at birth and persists throughout one’s life course. Though these disparate outcomes are evident, their causal mechanism is not yet clearly understood. Based on previous research, the authors suggest that implicit bias among healthcare providers is at least part of the answer.

This systematic review examines the bulk of literature published to date about the role of implicit bias among healthcare providers in racial and ethnic health disparities. In addition, the authors examine interventions intended to reduce bias in healthcare. 

Dr. Ivy W. Maina is a Resident Physician in Otolaryngology at the University of Pennsylvania affiliated hospitals and a Medical Writer for Buoy Health. Tanisha D. Belton is a Clinical Research Project Manager at the Children’s Hospital of Philadelphia. Dr. Sara Palazzo Ginzberg is a General Surgery Resident at the Hospital of the University of Pennsylvania and an Assistant Instructor in Surgery. Dr. Ajit Singh is a primary care provider and Resident at the Philadelphia College of Osteopathic Medicine. Dr. Tiffani J. Johnson is an Attending Physician in the Emergency Department and a Faculty Scholar at PolicyLab at the Children’s Hospital of Philadelphia.

Methods and Findings

The authors used standard protocol for systematic analyses, including defining their search terms: 1) healthcare providers, 2) implicit bias (measured using the Implicit Association Test only), and 3) racial/ethnic prejudice or stereotype activation. Next, they used these terms to search for relevant scientific articles published from 1997 to September 2016 in PubMed, PsycINFO, SCOPUS, and CINAHL. Each article was screened by two reviewers for inclusion into the meta-analysis based on standardized criteria, with a third reviewer resolving any disagreements. Of an initial 6249 articles (4934 after removal of duplicates), 29 studies passed the inclusion criteria and 8 additional studies were included from auto-search results. Two reviewers independently extracted relevant data from each study, including details about the study design, setting, participants, methods, and results, and the reported results were reviewed.

Overall, the 37 studies included 10,013 healthcare provider participants throughout the United States. The authors report four major findings:

Finding 1: Research shows that most healthcare providers — across multiple levels of training and disciplines — have implicit biases against Black, Latinx, Indigenous, and ‘dark skinned patients’ (terminology used by the researchers).

Finding 2: The level of bias differs based on provider characteristics: Black providers generally have little implicit racial bias compared to white, Latinx, and Asian providers.

Finding 3: Research about the impact of implicit bias on patient care and patient outcomes is limited; the authors identified only 7 studies that demonstrate a consistent association between higher provider implicit bias and poorer patient-provider interactions, while the rest report mixed results. Only the studies that examined real world patient-provider interactions, as opposed to simulated patients or clinical vignettes, demonstrated a clear association.

Finding 4: Only two published intervention studies tested methods to reduce implicit bias among healthcare providers, and only one demonstrated success in reducing implicit bias post-intervention.

Conclusions

Implicit bias plays a significant role in the provision of medical services. By examining a wide range of  literature, the authors demonstrate the role of provider implicit bias in healthcare and uncover significant gaps in existing research in both outcomes and reduction strategies.

Despite several limitations based on the studies included, the researchers’ systematic review and meta-analysis found that provider implicit bias contributes to health disparities, congruent with the findings of related studies. Furthermore, the authors suggest that patient-provider communication, particularly under the stresses of real-time interactions, may be the channel through which provider implicit associations lead to lower quality of clinical care and health outcomes.

The authors recommend additional research to uncover the impact of implicit provider bias on healthcare outcomes and to identify strategies to reduce provider implicit bias. Such studies would need to be more nationally representative of a wider base of patients and providers of different racial identities and lived experiences, and of geographic settings. The authors also identify several specific research areas for further exploration, including patient characteristics that impact patient-provider interactions; the impact of providers’ implicit negative stereotypes against Black, Indigenous and patients of color and their prescribed treatments; stress in healthcare provision and other system-level, setting, or specialty characteristics that may impact provider decision-making and implicit bias; how provider bias changes over time with increased clinical experience; the downstream effects of implicit bias on real world patient behavior and clinical outcomes; and successful methods to reduce provider implicit bias and sources of cognitive stress.

Review of healthcare research provides new insight in affirming common themes and findings, as well as gaps for further understanding.