title: A person based formula for allocating commissioning funds to general practices in England: development of a statistical model.
abstract: OBJECTIVE
  To develop a formula for allocating resources for commissioning hospital care to all general practices in England based on the health needs of the people registered in each practice
  
  
  METHODS
  Multivariate prospective statistical models were developed in which routinely collected electronic information from 2005-6 and 2006-7 on individuals and the areas in which they lived was used to predict their costs of hospital care in the next year, 2007-8. Data on individuals included all diagnoses recorded at any inpatient admission. Models were developed on a random sample of 5 million people and validated on a second random sample of 5 million people and a third sample of 5 million people drawn from a random sample of practices.
  
  
  METHODS
  All general practices in England as of 1 April 2007. All NHS inpatient admissions and outpatient attendances for individuals registered with a general practice on that date.
  
  
  METHODS
  All individuals registered with a general practice in England at 1 April 2007.
  
  
  METHODS
  Power of the statistical models to predict the costs of the individual patient or each practice's registered population for 2007-8 tested with a range of metrics (R(2) reported here). Comparisons of predicted costs in 2007-8 with actual costs incurred in the same year were calculated by individual and by practice.
  
  
  RESULTS
  Models including person level information (age, sex, and ICD-10 codes diagnostic recorded) and a range of area level information (such as socioeconomic deprivation and supply of health facilities) were most predictive of costs. After accounting for person level variables, area level variables added little explanatory power. The best models for resource allocation could predict upwards of 77% of the variation in costs at practice level, and about 12% at the person level. With these models, the predicted costs of about a third of practices would exceed or undershoot the actual costs by 10% or more. Smaller practices were more likely to be in these groups.
  
  
  CONCLUSIONS
  A model was developed that performed well by international standards, and could be used for allocations to practices for commissioning. The best formulas, however, could predict only about 12% of the variation in next year's costs of most inpatient and outpatient NHS care for each individual. Person-based diagnostic data significantly added to the predictive power of the models.
authors: The Nuffield Trust, London W1G 7LP, UK. jennifer.dixon@nuffieldtrust.org.uk
authors: Jennifer
authors: J
authors: Dixon
authors: Peter
authors: P
authors: Smith
authors: Hugh
authors: H
authors: Gravelle
authors: Steve
authors: S
authors: Martin
authors: Martin
authors: M
authors: Bardsley
authors: Nigel
authors: N
authors: Rice
authors: Theo
authors: T
authors: Georghiou
authors: Mark
authors: M
authors: Dusheiko
authors: John
authors: J
authors: Billings
authors: Michael De
authors: MD
authors: Lorenzo
authors: Colin
authors: C
authors: Sanderson
mesh_terms: D000328:Adult; D000368:Aged; D002017:Budgets; D003365:Costs and Cost Analysis; D004739:England; D005260:Female; D005376:Financial Management; D058006:General Practice / Q000191:economics* / Q000458:organization & administration; D006801:Humans; D008297:Male; D008875:Middle Aged; D018803:Models, Economic; D015999:Multivariate Analysis; D011446:Prospective Studies; D040841:Resource Allocation / Q000191:economics*; D013222:State Medicine / Q000191:economics