Background: Ethnic inequalities in access to health services are difficult to monitor and address because of limited data. Within the health service, ethnicity data have been poor quality, partly because they are not seen as useful.
Methods: The analysis related age- and sex-standardized coronary revascularization procedures to defined measures of need, using proportional ratios derived from Hospital Episode Statistics records for London residents admitted to any hospital nationally in 2002-03 or 2003-04.
Results: Although 2001 Ethnicity Categories were mandatory for the NHS from April 2001, by 2003-04 >20% of coronary heart disease (CHD) records still had no ethnic category coded. Hospital admission for CHD and revascularization by ethnicity varied widely, following known patterns of CHD incidence and mortality. There is much less variation between ethnic groups when comparing revascularization rate relative with CHD admission rates (whether all or emergencies). However, Bangladeshi patients had only two-thirds [proportional ratio 66.8, 95% confidence interval (CI) 60.7-73.3] and Black Caribbean and Black African patients four-fifths (proportional ratios 80.5, 72.0-89.9 and 80.7, 68.0-95.2, respectively) the revascularization rate in comparison with apparent need as the general population.
Conclusion: Even with imperfect data, the analysis of routine data can identify inequalities that warrant further investigation.