title: The contribution of physician assistants in primary care: a systematic review.
abstract: BACKGROUND
  Primary care provision is important in the delivery of health care but many countries face primary care workforce challenges. Increasing demand, enlarged workloads, and current and anticipated physician shortages in many countries have led to the introduction of mid-level professionals, such as Physician Assistants (PAs).
  
  
  OBJECTIVE
  This systematic review aimed to appraise the evidence of the contribution of PAs within primary care, defined for this study as general practice, relevant to the UK or similar systems.
  
  
  METHODS
  Medline, CINAHL, PsycINFO, BNI, SSCI and SCOPUS databases were searched from 1950 to 2010.
  
  
  METHODS
  PAs with a recognised PA qualification, general practice/family medicine included and the findings relevant to it presented separately and an English language journal publication. Two reviewers independently identified relevant publications, assessed quality using Critical Appraisal Skills Programme tools and extracted findings. Findings were classified and synthesised narratively as factors related to structure, process or outcome of care.
  
  
  RESULTS
  2167 publications were identified, of which 49 met our inclusion criteria, with 46 from the United States of America (USA). Structure: approximately half of PAs are reported to work in primary care in the USA with good support and a willingness to employ amongst doctors.
  
  
  METHODS
  the majority of PAs' workload is the management of patients with acute presentations. PAs tend to see younger patients and a different caseload to doctors, and require supervision. Studies of costs provide mixed results.
  
  
  RESULTS
  acceptability to patients and potential patients is consistently found to be high, and studies of appropriateness report positively. Overall the evidence was appraised as of weak to moderate quality, with little comparative data presented and little change in research questions over time.
  
  
  CONCLUSIONS
  identification of a broad range of studies examining 'contribution' made meta analysis or meta synthesis untenable.
  
  
  CONCLUSIONS
  The research evidence of the contribution of PAs to primary care was mixed and limited. However, the continued growth in employment of PAs in American primary care suggests that this professional group is judged to be of value by increasing numbers of employers. Further specific studies are needed to fill in the gaps in our knowledge about the effectiveness of PAs' contribution to the international primary care workforce.
authors.affiliation: Faculty of Health and Social Care Sciences, Kingston University and St George's, University of London, Cranmer Terrace, London SW17 0RE, UK. m.halter@sgul.kingston.ac.uk
authors.forename: Mary
authors.initials: M
authors.lastname: Halter
authors.forename: Vari
authors.initials: V
authors.lastname: Drennan
authors.forename: Kaushik
authors.initials: K
authors.lastname: Chattopadhyay
authors.forename: Wilfred
authors.initials: W
authors.lastname: Carneiro
authors.forename: Jennifer
authors.initials: J
authors.lastname: Yiallouros
authors.forename: Simon
authors.initials: S
authors.lastname: de Lusignan
authors.forename: Heather
authors.initials: H
authors.lastname: Gage
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gabe
authors.forename: Robert
authors.initials: R
authors.lastname: Grant
mesh_terms: D001315:Australia; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands; D010823:Physician Assistants / Q000191:economics / Q000458:organization & administration / Q000600:supply & distribution*; D011320:Primary Health Care / Q000191:economics / Q000458:organization & administration; D006113:United Kingdom; D014481:United States; D014940:Work Schedule Tolerance; D000078329:Workforce