Abstract
STUDY OBJECTIVES: Equity should be monitored routinely for all health care services, but ideal studies for each service would be prohibitively expensive and time consuming. A simple, quick, and cheap method for the preliminary exploration of equity in health care provision using routine data was devised. This method was illustrated by examining whether coronary artery bypass graft (CABG) operations reflect socioeconomic differences in ischaemic heart disease (IHD) mortality. DESIGN: Ecological comparison of operation rates was undertaken for CABG for 1991 and IHD mortality for 1981-85 by quartiles of Townsend deprivation score. SETTING: North East Thames Regional Health Authority, London, UK. SUBJECTS: All residents of this region aged 35-74 were the denominator population. Numerators were 26,834 IHD deaths and 1041 CABG operations for the defined time periods. MAIN RESULTS: IHD mortality showed a steady, significant increase with increasing area deprivation scores for both men and women. CABG rate ratios increased linearly for women, while for men there was a U shaped pattern, being lowest for the second and third quartiles. This pattern was attenuated, but not abolished, when adjusted for geographical proximity to cardiothoracic surgical units. The ratio of CABG operations to IHD mortality by deprivation was relatively constant in women suggesting equitable provision. In men, this ratio was significantly lower for the third quartile. CONCLUSIONS: Inequities may exist in the provision of CABG operations for men in this region and this finding should be the stimulus for further detailed studies. Other health care systems should also examine equity in provision.