Measuring change in health care equity using small area administrative data – evidence from the English NHS 2001-8

This study developed a method for measuring change in socio-economic equity in health care utilisation using small area level administrative data. Our method provides more detailed information on utilisation than survey data but only examines socio-economic differences between neighbourhoods rather than individuals. The context was the English NHS from 2001 to 2008, a period of accelerated expenditure growth and pro-competition reform. Hospital records for all adults receiving non-emergency hospital care in the English NHS from 2001 to 2008 were aggregated to 32,482 English small areas with mean population about 1,500 and combined with other small area administrative data. Regression models of utilisation were used to examine year-on-year change in the small area association between deprivation and utilisation, allowing for population size, age-sex composition and disease prevalence including (from 2003-8) cancer, chronic kidney disease, coronary heart disease, diabetes, epilepsy, hypertension, hypothyroidism, stroke, transient ischaemic attack and (from 2006-8) atrial fibrillation, chronic obstructive pulmonary disease, obesity and heart failure. There was no substantial change in small area associations between deprivation and utilisation for outpatient visits, hip replacement, senile cataract, gastroscopy or coronary revascularisation, though overall non-emergency inpatient admissions rose slightly faster in more deprived areas than elsewhere. Associations between deprivation and disease prevalence changed little during the period, indicating that observed need did not grow faster in more deprived areas than elsewhere. We conclude that there was no substantial deterioration in socio-economic equity in health care utilisation in the English NHS from 2001 to 2008, and if anything, there may have been a slight improvement.