Are variations in the use of carotid endarterectomy explained by population Need? A study of health service utilisation in two English health regions.

OBJECTIVES to describe variation in utilisation of carotid endarterectomy (CEA) within two English health regions and explore relationships between use, need and proximity to services. DESIGN consecutive case series of operations. Comparison at a population level with district stroke mortality, hospital admissions and material deprivation. MAIN OUTCOME MEASURES standardised utilisation rates for CEA and measures of inter-district variability. Spearman's rank correlation coefficients for associations between variables. RESULTS variation in utilisation rates was considerable (14-fold difference across district populations). More individuals had bilateral surgery in the Yorkshire region than in the Northern (11.7% vs. 5.5%, p=0.002). There was no association between utilisation rates for CEA and district stroke mortality (r=-0.06, 95% CI -0.41 to 0.30) or admission rates for stroke (r=0.17, 95% CI -0.2 to 0.49). There was a strong relationship between residence in districts where services were located and higher utilisation. Rates of CEA were lowest in the regions' most affluent wards. CONCLUSION use of CEA varies widely, depending on area of residence. Variation is not a consequence of differences in need, but reflects clinical practice and supply of services. There is evidence to suggest unmet need for CEA.