Primary care capitation payments in the UK. An observational study

Table 1 Indices used in allocation formula

Index	Brief description of index	Interquartile range^†	Change in percentage explained^‡
Age Sex Index	Compensates for higher consulting rates for women and patients at the extremes of age by weighting patients according to age and sex	0.93 - 1.05	39%
Additional Needs Index	Deprivation related clinical workload indicator generated using Standard Mortality and Long Standing Illness data	0.91 - 1.10	58%
Rurality Index	Generated from population density data and average distance of patients' homes from the practice main surgery	0.97 - 1.01	11%
MFF* Index	Represents local labour costs and calculated according to the practice main surgery address	0.97 - 1.02	7%
List Turnover Index	Compensates for high patient turnover and generated from counts of new patients	0.99 - 1.01	3%
NRH* Index	Compensates for additional home visits generated by patients in nursing and residential care	1.00 - 1.00	3%

† Original formula data for English and Welsh practices (1-4-2007).
‡ Change in percentage explained if index is removed from a multiple regression model containing all indices as predictors for overall Carr-Hill formula weighting (original formula data 2007). The model with all indices explains 97% of the variation of Carr-Hill weighting.
* MFF denotes Market Forces Factor and NRH Nursing and Residential Home patients.

ISSN: 1472-6963