Reconciling heart disease mortality and ICD codes.

Area of Science:

• Cardiovascular epidemiology
• Public health surveillance
• Historical mortality trends

Background:

• Heart disease mortality trends provide insights into population health and healthcare effectiveness.
• Understanding historical patterns is crucial for contemporary public health interventions.
• Coding system evolution impacts the reliability of long-term health data analysis.

Purpose of the Study:

• To describe the transition in heart disease mortality in Bexar County, Texas, from 1935 to 1995.
• To analyze changes in life expectancy for individuals with heart disease over six decades.
• To identify trends in specific types of heart disease, including acute and chronic ischemic heart disease.

Main Methods:

• Utilized 61 years of death certificate data (1935-1995) for Bexar County, Texas.
• Employed data uniformly coded under the International Classification of Diseases, 9th Revision (ICD-9).
• Analyzed trends in heart disease mortality and associated life expectancy changes.

Main Results:

• Life expectancy for those dying with heart disease increased significantly during the study period.
• Distinct differences in the rate of increase were observed between males and females.
• A notable epidemic of acute ischemic heart disease (AIHD) occurred in the 1950s and 1960s, which has since declined.

Conclusions:

• The study highlights a historical epidemic of AIHD, now showing signs of abatement.
• Findings suggest caution when conducting socioeconomic analyses of heart disease mortality due to coding convention instability.
• Changes in coding emphasis over time limit the confidence in tracing certain major heart diseases.