(176) Translating population-level epidemiology to patient need

Background: Among the hundreds of health conditions systematically measured as part of the Global Burden of Disease Study (GBD), coordinated by the Institute for Health Metrics and Evaluation (IHME), dental caries are the most prevalent and ischemic heart disease leads to the most deaths across the world. While these population-level metrics provide very useful information for priority setting and resource allocation, complementary metrics which focus on the typical patient experience may justify investments in improved prevention or treatment options.

Objectives: This study aims to evaluate and compare the severity of conditions for “average” patients by transforming population-level burden measures estimated from GBD into patient-level measures.

Methods: Leveraging the modelling framework and standard outputs from GBD, we computed the ratio of total condition-specific health loss in the population in a given calendar year (expressed as Disability Adjusted Life Years [DALYs]) to the total number of cases estimated to have occurred each year. DALYs are an aggregate burden measure pioneered by IHME which combines health loss due to mortality and disability. We use GBD prevalence estimates to determine the number of cases of chronic conditions, incidence estimates for acute conditions, and mortality estimates for conditions that are immediately fatal, such as SIDS. We estimated this measure of patient need (DALYs per case) for 236 conditions for every country and at the global level in the year 2021.

Results: Dental caries, while common (with an estimated 2.3 billion new cases in 2021) resulted in just 0.00016 disability adjusted life years per case, the second lowest of the 236 conditions. Ischemic heart disease led to 188 million DALYs globally in 2021, the condition with the second highest overall population-level burden after COVID-19. The average case of IHD experiences 0.75 DALYs. In contrast, liver cancer due to hepatitis C leads to just over 15 DALYs per case while there are only 3 million DALYs across the globe in 2021, only 0.11% of DALYs overall. An extreme example of a condition with relatively low population-level burden but high patient need is rabies with an estimated 56 DALYs per case, among the five highest conditions.

Conclusions: Translating IHME’s population-level disease burden metrics into patient-level metrics underscores the large differences in burden experienced by average patients suffering from different conditions. This novel patient-level measure, in conjunction with population-level burden estimates generated by IHME, can help organizations to identify conditions with the greatest unmet need for intervention – both at the population-level and at the individual-level.