Impact of physician assistants on quality of care: rapid review

Abstract

Objective: To determine the impact of physician assistants, compared with physicians, on quality of care in the context of an ongoing UK policy review.

Design: Rapid systematic review.

Search strategy: Keyword search of three databases; search and citation tracking of previous systematic reviews.

Eligibility criteria: Empirical studies that quantitatively compared care delivered by physician assistants with care delivered by physicians, including residents, in economically developed countries, published between January 2005 and January 2025.

Main outcomes of interest: Measures of outcomes of care, as defined by the Institute of Medicine's definition of quality: safety, effectiveness, patient centredness, timeliness, efficiency, and equity.

Methods: Eligible studies were categorised as primary care, secondary care, physician assistants versus residents in hospitals, diagnosis/performance, and cost effectiveness. Two reviewers independently extracted data on study design, samples, methods, and findings. Each study was assessed using a risk of bias tool. Owing to the heterogeneity of included studies, a narrative synthesis of the main findings was conducted. An assessment of confidence in the body of evidence for each outcome was based on the number and quality of relevant studies and the consistency of results between similar studies.

Results: Of 3636 studies screened, 167 studies were eligible and 40 met the inclusion criteria. These consisted mainly of retrospective observational studies of weak quality. Most (31/40) were from the US, and no data from a post-covid-19 context were found. The greatest number of studies with the most consistent results were those that found that physician assistants practised safely and effectively when working under direct supervision and in post-diagnostic care. No difference was found in patient satisfaction between physician assistants and physicians. Although adding physician assistants to medical teams increases access to care, this may reflect the benefits of increased staffing rather than the unique contribution of the physician assistant role. Evidence on cost effectiveness is limited. Patients in the UK are more likely to see a physician assistant if they live in a socioeconomically deprived area.

Conclusion: The evidence found in this review is limited and does not support the safety or effectiveness of indirect supervision of physician assistants in undifferentiated (pre-diagnosis) settings. National guidance on the supervision and scope of practice for physician assistants can ensure that physician assistants practise safely and effectively.

Study registration: PROSPERO CRD42024614992.

Fig 1

PRISMA diagram. *Did not meet inclusion criteria: not comparing physician assistant (PA) care with physician care (n=6); comparing different PA staffing models (n=1); reporting impact of PAs being added to medical teams (n=23); describing processes of care (n=18); self-reported competence/outcomes (n=6); systematic review (n=5). NP=nurse practitioner