OBJECTIVE: To estimate the effect of calculating the Jarman index using the smaller geographical unit of the census enumeration district on the changes in deprivation payments made to general practitioners. The Jarman index, or underprivileged area score, is used to calculate the allowance that general practices in the United Kingdom receive for each patient registered with them who lives in an area of relative social deprivation. Current values of the Jarman score are derived from the 1981 census and are based on electoral wards. The change in payments to some practices brought about by using data from the 1991 census may cause severe financial hardship. DESIGN: Jarman indices for wards and enumeration districts from the 1981 and 1991 censuses were used to calculate the payments made to 169 practices in Lambeth, Southwark, and Lewisham; the changes in payments under ward and enumeration district based schemes were then compared. MAIN OUTCOME MEASURES: Standard deviations of the changes in payments to practices. Extreme values of changes in payments. RESULTS: The standard deviation of the change in payment between the two censuses was 6365 pounds with the enumeration district Jarman index, whereas it was 9452 pounds under the ward based scheme. If the ward based scheme is used 10 practices would find their payments changed by over 20,000 pounds, whereas only two practices would have changed by more than this amount under the scheme based on enumeration districts. CONCLUSION: The Jarman index could be more sensitively and appropriately applied to calculate the deprivation payments that practices receive using the census enumeration district as its unit for calculation. This would result in fewer precipitate changes in payments when census data change every 10 years.
OBJECTIVE: To estimate the effect of calculating the Jarman index using the smaller geographical unit of the census enumeration district on the changes in deprivation payments made to general practitioners. The Jarman index, or underprivileged area score, is used to calculate the allowance that general practices in the United Kingdom receive for each patient registered with them who lives in an area of relative social deprivation. Current values of the Jarman score are derived from the 1981 census and are based on electoral wards. The change in payments to some practices brought about by using data from the 1991 census may cause severe financial hardship. DESIGN: Jarman indices for wards and enumeration districts from the 1981 and 1991 censuses were used to calculate the payments made to 169 practices in Lambeth, Southwark, and Lewisham; the changes in payments under ward and enumeration district based schemes were then compared. MAIN OUTCOME MEASURES: Standard deviations of the changes in payments to practices. Extreme values of changes in payments. RESULTS: The standard deviation of the change in payment between the two censuses was 6365 pounds with the enumeration district Jarman index, whereas it was 9452 pounds under the ward based scheme. If the ward based scheme is used 10 practices would find their payments changed by over 20,000 pounds, whereas only two practices would have changed by more than this amount under the scheme based on enumeration districts. CONCLUSION: The Jarman index could be more sensitively and appropriately applied to calculate the deprivation payments that practices receive using the census enumeration district as its unit for calculation. This would result in fewer precipitate changes in payments when census data change every 10 years.