Are epidemic growth rates more informative than reproduction numbers?. (26th May 2022)

• Record Type: Journal Article
• Authors: Parag, Kris V.; Thompson, Robin N.; Donnelly, Christl A.
• Is Part Of: Journal of the Royal Statistical Society. Volume 185(2022)Supplement 1
• Page Start: S5
• Page End: S15
• Publication Date: 2022-05-26
• Subjects: COVID‐19 -- epidemic modelling -- growth rate -- infectious disease -- reproduction number -- situational awareness; Social sciences -- Statistical methods -- Periodicals; Statistics -- Periodicals; 300.15195
• DOI: 10.1111/rssa.12867
• Languages: English
• ISSNs: 0964-1998

Abstract

Abstract: Summary statistics, often derived from simplified models of epidemic spread, inform public health policy in real time. The instantaneous reproduction number, R t, is predominant among these statistics, measuring the average ability of an infection to multiply. However, R t encodes no temporal information and is sensitive to modelling assumptions. Consequently, some have proposed the epidemic growth rate, r t, that is, the rate of change of the log‐transformed case incidence, as a more temporally meaningful and model‐agnostic policy guide. We examine this assertion, identifying if and when estimates of r t are more informative than those of R t . We assess their relative strengths both for learning about pathogen transmission mechanisms and for guiding public health interventions in real time.