The impact of introducing ICD-10 on trends in mortality from circulatory diseases in England and Wales.

This article examines the impact of the introduction of ICD-10 on mortality from circulatory diseases in England and Wales. The article examines changes to specific types of circulatory disease, focussing on ischaemic heart disease (IHD) and cerebrovascular disease (stroke). The main changes are highlighted and the article explains how data can be adjusted to take account of these changes so that trends over time can be analysed. The article then looks at the impact of the changes on baselines for Government targets to reduce mortality from circulatory diseases. The number of deaths assigned to circulatory diseases increases by 3-4 per cent as a result of the introduction of ICD-10, replacing ICD-9. For cerebrovascular diseases specifically, the increase is 9 per cent for females and 13 per cent for males. Trends in mortality from IHD are unaffected by the introduction of ICD-10. However, the number of deaths assigned to acute myocardial infarction, which forms part of IHD, decreases by around 10 per cent when ICD-10 is used instead of ICD-9.