Applications of Extreme Value Theory in Public Health.

Maud Thomas,Youri Yordanov,Hans Wackernagel,Cécile Viboud,Fabrice Carrat,Mark L Wilson,Magali Lemaitre,Chris T Bauch

doi:10.1371/journal.pone.0159312

Abstract

ObjectivesWe present how Extreme Value Theory (EVT) can be used in public health to predict future extreme events.MethodsWe applied EVT to weekly rates of Pneumonia and Influenza (P&I) deaths over 1979–2011. We further explored the daily number of emergency department visits in a network of 37 hospitals over 2004–2014. Maxima of grouped consecutive observations were fitted to a generalized extreme value distribution. The distribution was used to estimate the probability of extreme values in specified time periods.ResultsAn annual P&I death rate of 12 per 100,000 (the highest maximum observed) should be exceeded once over the next 30 years and each year, there should be a 3% risk that the P&I death rate will exceed this value. Over the past 10 years, the observed maximum increase in the daily number of visits from the same weekday between two consecutive weeks was 1133. We estimated at 0.37% the probability of exceeding a daily increase of 1000 on each month.ConclusionThe EVT method can be applied to various topics in epidemiology thus contributing to public health planning for extreme events.

Highlights

A central question for resource planning in public health is to predict the likelihood that exceptional or extreme events will occur in the not too distant future [1]
The Extreme Value Theory (EVT) method can be applied to various topics in epidemiology contributing to public health planning for extreme events
The aim of this paper is to present how EVT can be applied in public health

Summary

Introduction

A central question for resource planning in public health is to predict the likelihood that exceptional or extreme events will occur in the not too distant future [1]. Such events might be, for example, an unusual community epidemic, a major heat wave, or an accidental toxic exposure. Extreme Value Theory (EVT) was developed in the 1920s [2] and has been used to predict the occurrence of events as varied as droughts and flooding [3] or financial crashes [4]. In a first unpublished work we applied the method to predict extreme influenza mortality in the US [5]. A study applied EVT to predict monthly incidence of avian influenza cases [7]

Objectives

Methods

Conclusion