The Devils in the DALY: Prevailing Evaluative Assumptions.

Area of Science:

• Global Health Metrics
• Epidemiology
• Health Economics

Background:

• The Global Burden of Disease (GBD) study is a major source of health metric data.
• The disability-adjusted life year (DALY) is a key metric used by the GBD study.
• Recent GBD publications (2010 onwards) have omitted time discounting and age-weighting from the DALY model.

Purpose of the Study:

• To analyze the evaluative nature of the DALY metric.
• To compare the DALY's assumptions across different phases of the GBD study (1990-1996 vs. 2010-2017).
• To determine if the DALY has become primarily descriptive or remains evaluative.

Main Methods:

• Comparative analysis of DALY assumptions in GBD publications.
• Categorization of underlying assumptions as descriptive or evaluative.
• Examination of changes in the DALY model between the early GBD phase and recent releases.

Main Results:

• The DALY metric, despite revisions, retains significant evaluative components.
• The omission of time discounting and age-weighting has not rendered the DALY purely descriptive.
• The DALY continues to incorporate implicit or explicit value judgments.

Conclusions:

• The DALY, by its nature and application, remains a largely evaluative measure of disease burden.
• While efforts have been made to increase the descriptiveness of the DALY, its evaluative aspects are inherent.
• Understanding the evaluative nature of the DALY is crucial for its accurate interpretation and application in health policy.