title: Association between primary care organisation population size and quality of commissioning in England: an observational study.
abstract: BACKGROUND
  The ideal population size of healthcare commissioning organisations is not known.
  
  
  OBJECTIVE
  To investigate whether there is a relationship between the size of commissioning organisations and how well they perform on a range of performance measures.
  
  
  METHODS
  Cross-sectional, observational study of performance in all 152 primary care trusts (PCTs) in England.
  
  
  METHODS
  Comparison of PCT size against 36 indicators of commissioning performance, including measures of clinical and preventative effectiveness,  patient centredness, access, cost, financial ability, and engagement.
  
  
  RESULTS
  Fourteen of the 36 indicators have an unadjusted relationship (P<0.05) with size of the PCT. With 10 indicators, there was increasing quality with larger size. However, when population  factors including deprivation, ethnicity, rurality, and age were included in the analysis, there was no relationship between size and performance for any measure.
  
  
  CONCLUSIONS
  There is no evidence to suggest that there is an optimum size for PCT performance. Observed variations  in PCT performance with size were explained by the characteristics of the populations they served. These findings suggest that configuration of clinical commissioning groups should be geared towards producing organisations that can function effectively across their key responsibilities, rather  than being based on the size of their population alone.
authors.affiliation: Department of Primary Care and Public Health, Imperial College London, London. felix.greaves08@imperial.ac.uk
authors.forename: Felix
authors.initials: F
authors.lastname: Greaves
authors.forename: Christopher
authors.initials: C
authors.lastname: Millett
authors.forename: Utz J
authors.initials: UJ
authors.lastname: Pape
authors.forename: Michael
authors.initials: M
authors.lastname: Soljak
authors.forename: Azeem
authors.initials: A
authors.lastname: Majeed
mesh_terms: D003430:Cross-Sectional Studies; D017598:Efficiency, Organizational; D004739:England; D006801:Humans; D011156:Population Density; D011320:Primary Health Care / Q000458:organization & administration / Q000592:standards* / Q000706:statistics & numerical data; D019984:Quality Indicators, Health Care; D013222:State Medicine / Q000458:organization & administration / Q000592:standards* / Q000706:statistics & numerical data