Comparability of COVID-19 Epidemiological Data

Bangladesh, Burkina Faso, Colombia, Democratic Republic of the Congo, Nigeria, Syria
December 1, 2021
Case Study

Executive Summary


Cross-country comparisons of COVID-19 data are important to understand differences in the burden of COVID-19, determine countries’ relative success containing the virus and guide policies. The comparison of COVID-19 epidemiological data across countries is, however, challenging due to differences in terms of how data are collected and reported.

Research questions The objective of this research was to assess issues associated with comparing national-level COVID-19 epidemiological data in six countries: Bangladesh Burkina Faso, Colombia, DRC, Nigeria and Syria. Specifically, this report sought to address the following questions:

What is the state of the COVID-19 pandemic in Burkina Faso, Colombia, DRC, Nigeria, Bangladesh, and Syria?
How do indicators used to measure COVID-19 testing, cases and mortality differ across the six countries?
What factors may have an impact on the accuracy of COVID-19 indicators and observed differences across countries?

What COVID-19 indicators and information should be reported to increase comparability across countries?
Methodology This research consisted of two data collection methods: secondary data review and semistructured key informant interviews. A review of the grey and peer-reviewed literature was conducted, and key informants were interviewed in Burkina Faso and Nigeria Key findings: This analysis revealed that data collection, measurement and reporting practices for COVID-19 testing, case identification, and mortality vary greatly across the six countries. As a result of data availability and quality issues, COVID-19 measures often either underestimate or overestimate the number of people tested, cases identified and people dying from COVID-19 to varying degrees across countries. Factors that lead to differences in COVID-19 data comparability include: variability in testing strategies including testing availability, eligibility criteria, cost of testing and contact tracing efforts; differing case definitions and use of COVID-19 tests; and overall lack of documentation regarding how indicators are measured. Ambiguous information is particularly prevalent for mortality calculations. Cross-country comparisons are also subject to key differences in reporting practices and contextual factors that may not be documented. When they are not addressed, these country-specific biases and cross-country differences lead to biased comparisons.

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