Assessing and Measuring Chronic Multimorbidity in the Older Population: A Proposal for Its Operationalization

Area of Science:

• Gerontology
• Public Health
• Clinical Epidemiology

Background:

• Multimorbidity, defined as multiple chronic diseases, lacks standardized operationalization.
• Existing definitions hinder consistent measurement and comparison of disease burden.

Purpose of the Study:

• To develop a clinically driven, comprehensive list of chronic conditions for measuring multimorbidity.
• To operationalize multimorbidity assessment using the International Classification of Diseases, 10th revision (ICD-10).

Main Methods:

• International multidisciplinary team classified ICD-10 codes as chronic based on duration and impact.
• Chronic codes were grouped into clinical categories.
• Proof of concept applied to older adults in the Swedish National study of Aging and Care in Kungsholmen (SNAC-K) and inpatient data.

Main Results:

• A consensus definition identified 918 chronic ICD-10 codes, grouped into 60 categories.
• High prevalence of multimorbidity observed: 88.6% had ≥2 categories, 73.2% had ≥3, and 55.8% had ≥4.
• The classification is applicable to both clinical and administrative data.

Conclusions:

• This operational measure facilitates multimorbidity monitoring and international comparison.
• Validated measures can advance conceptual understanding and improve patient care.
• The study provides a robust framework for assessing multimorbidity prevalence.