🤖 AI Summary
Existing epidemiological forecasting models—both empirical and mechanistic—exhibit markedly reduced accuracy during outbreak peaks, especially at the peak itself. To address this, we propose *epimodulation*, a novel framework that enables lightweight, plug-and-play, dynamic integration of domain-specific epidemiological knowledge (e.g., trends in the basic reproduction number ℛ₀ and transmission thresholds) with mainstream time-series models—including ARIMA, Holt-Winters, spline-based methods, and ensemble forecasts from the COVID-19 Forecast Hub. Crucially, this hybrid paradigm imposes dynamical constraints *during* prediction without requiring architectural modifications to the base models. Evaluated on COVID-19 and influenza hospitalization data, epimodulation improves overall forecast accuracy by 9.1% and 19.5%, respectively, and achieves substantially larger gains—20.7% and 25.4%—during peak outbreak periods. These results demonstrate marked enhancement in the robustness and reliability of short-term forecasts during critical public health response windows.
📝 Abstract
Accurate forecasts of disease outbreaks are critical for effective public health responses, management of healthcare surge capacity, and communication of public risk. There are a growing number of powerful forecasting methods that fall into two broad categories -- empirical models that extrapolate from historical data, and mechanistic models based on fixed epidemiological assumptions. However, these methods often underperform precisely when reliable predictions are most urgently needed -- during periods of rapid epidemic escalation. Here, we introduce epimodulation, a hybrid approach that integrates fundamental epidemiological principles into existing predictive models to enhance forecasting accuracy, especially around epidemic peaks. When applied to simple empirical forecasting methods (ARIMA, Holt--Winters, and spline models), epimodulation improved overall prediction accuracy by an average of 9.1% (range: 8.2--12.5%) for COVID-19 hospital admissions and by 19.5% (range: 17.6--23.2%) for influenza hospital admissions; accuracy during epidemic peaks improved even further, by an average of 20.7% and 25.4%, respectively. Epimodulation also substantially enhanced the performance of complex forecasting methods, including the COVID-19 Forecast Hub ensemble model, demonstrating its broad utility in improving forecast reliability at critical moments in disease outbreaks.