Cross sectional study of primary care groups in London: association of measures of socioeconomic and health status with hospital admission rates.

OBJECTIVES To calculate socioeconomic and health status measures for the primary care groups in London and to examine the association between these measures and hospital admission rates. DESIGN Cross sectional study. SETTING 66 primary care groups in London, total list size 8.0 million people. MAIN OUTCOME MEASURES Elective and emergency standardised hospital admission ratios; standardised admission rates for diabetes and asthma. RESULTS Standardised hospital admission ratios varied from 74 to 116 for total admissions and from 50 to 124 for emergency admissions. Directly standardised admission rates for asthma varied from 152 to 801 per 100 000 (mean 364) and for diabetes from 235 to 1034 per 100 000 (mean 538). There were large differences in the mortality, socioeconomic, and general practice characteristics of the primary care groups. Hospital admission rates were significantly correlated with many of the measures of chronic illness and deprivation. The strongest correlations were with disability living allowance (R=0.64 for total admissions and R=0.62 for emergency admissions, P<0.0001). Practice characteristics were less strongly associated with hospital admission rates. CONCLUSIONS It is feasible to produce a range of socioeconomic, health status, and practice measures for primary care groups for use in needs assessment and in planning and monitoring health services. These measures show that primary care groups have highly variable patient and practice characteristics and that hospital admission rates are associated with chronic illness and deprivation. These variations will need to be taken into account when assessing performance.