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 u se, need and proximity to sevices. Design: consecutive case series of operations. Comparison at a population l evel with district stroke mortality, hospital admissions and material depri vation. Main outcome measures: standardised utilisation rates for CEA and measures of inter-district variability. Spearman's mirk correlation coefficients for associations between variables. Results: variation in utilization rates was considerable (14-fold differenc e across district populations). More individuals had bilateral surgery in t he 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 m ortality (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 res idence in districts where services were located and higher utilisation. Rat es of CEA were lowest in the regions' most affluent wards. Conclusion: use of CEA val ies widely, depending on area of residence. Vari ation is not a consequence of differences in need, brit reflects clinical p ractice and supply of services. There is evidence to suggest unmet need for CEA.