COIOSDeep risk insights through multi-disciplinary research across the globe
Ornate building facade with flags in washington
Item refines Peer-reviewed Added

Ensemble models of expected US mortality were more accurate than single models

Using weekly US deaths for 2008–2024, ensemble models gave more accurate expected mortality, with better coverage, than single models.

The study tested ensemble models for estimating expected mortality, the baseline against which excess deaths are measured. It used weekly death counts for the United States from the National Vital Statistics System, 2008 to 2024. The authors compared 76 candidate models, with different long-term and seasonal trend specifications, against ensemble models. Ensembles performed more consistently and robustly, with better accuracy and interval coverage than individual models. The abstract does not report the size of these gains in accuracy or coverage.

Why it is interesting: Excess mortality estimates after COVID-19 have varied with the model and analytic choices used. Pooling many trend specifications reduces how far the expected baseline depends on any one of those choices.

Source
Epidemiologic Methods, 24 October 2026
Paper
An ensemble modeling approach for estimating expected patterns in mortality in the United States
Authors
Rossen LM, Cisewski JA, Ahmad FB, Anderson RN
DOI
10.1515/em-2025-0035
Type
Peer-reviewed article
Design
Methods comparison of 76 candidate and ensemble models for expected mortality, US weekly NVSS data 2008-2024, evaluated on accuracy and interval coverage
Verdict
Refines prior evidence
Driver
Forecasts and their record
Driver
Infection and pandemics
Free full text
Free copy in a repository (submitted manuscript)

Other drivers in Data, models and systems