Consistency of daily number of reported COVID-19 cases in 191 countries between two major data sources, 2020-2022 (Preprint)

Abstract

The coronavirus disease 2019 (COVID-19) pandemic is among the greatest global public health challenges of this century.The WHO and the Johns Hopkins University Center for Systems Science and Engineering (JHU CSSE) were two open-access data sources which were widely used in research and decision-making about the COVID-19 epidemic.High-quality data is one key aspect of public health crisis and pandemic preparedness for decision-making, practice, and research about prevention and control. To better respond to pandemics and other health crises in the future, it is necessary to evaluate the quality of pandemic data to improve rapid response to outbreaks.

To evaluate consistency of daily reported Coronavirus disease 2019 (COVID-19) cases in 191 countries from the Johns Hopkins University Center for Systems Science and Engineering (JHU CSSE) and the World Health Organization (WHO) dashboards during 2020-2022.

We retrieved data concerning new daily COVID-19 cases in 191 countries covered by both data sources from January 22, 2020, to December 31, 2022. The ratio of numbers of daily reported cases from the two sources were calculated to measure data consistency. We performed simple linear regression to examine significant changes in the ratio of numbers of daily reported cases during the study period.

Of 191 WHO member countries, only 60 displayed excellent data consistency in the number of daily reported COVID-19 cases between the WHO and JHU CSSE dashboards (case number ratio: 0.9-1.1). Data consistency changed greatly across the 191 countries from 2020 to 2022 and differed across four types of countries, defined by income. Data inconsistency between the two data sources generally decreased slightly over time, both for the 191 countries combined and within the four types of income-defined countries. The absolute relative difference between two data sources increased in 84 countries (particularly for Malta, Montenegro, and United States, R2=0.29) but decreased in 40 countries (P<0.05).

The inconsistency between the two data sources warrants further research. Construction of public health surveillance and data collection systems for public health emergencies like the COVID-19 pandemic should be strengthened in the future.