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COVID-19 Case Age Distribution: Correction for Differential Testing by Age
- Source :
- Annals of Internal Medicine
- Publication Year :
- 2021
- Publisher :
- American College of Physicians, 2021.
-
Abstract
- This population-based cohort study evaluated whether differences in COVID-19 incidence between children and adults in Ontario could be accounted for by differences in testing. The authors developed an approach that permits adjustment for differential relationships between testing and risk in different age and sex groups in the population.<br />Background: Despite expected initial universal susceptibility to a novel pandemic pathogen like SARS-CoV-2, the pandemic has been characterized by higher observed incidence in older persons and lower incidence in children and adolescents. Objective: To determine whether differential testing by age group explains observed variation in incidence. Design: Population-based cohort study. Setting: Ontario, Canada. Participants: Persons diagnosed with SARS-CoV-2 and those tested for SARS-CoV-2. Measurements: Test volumes from the Ontario Laboratories Information System, number of laboratory-confirmed SARS-CoV-2 cases from the Integrated Public Health Information System, and population figures from Statistics Canada. Demographic and temporal patterns in incidence, testing rates, and test positivity were explored using negative binomial regression models and standardization. Sources of variation in standardized ratios were identified and test-adjusted standardized infection ratios (SIRs) were estimated by metaregression. Results: Observed disease incidence and testing rates were highest in the oldest age group and markedly lower in those younger than 20 years; no differences in incidence were seen by sex. After adjustment for testing frequency, SIRs were lowest in children and in adults aged 70 years or older and markedly higher in adolescents and in males aged 20 to 49 years compared with the overall population. Test-adjusted SIRs were highly correlated with standardized positivity ratios (Pearson correlation coefficient, 0.87 [95% CI, 0.68 to 0.95]; P < 0.001) and provided a case identification fraction similar to that estimated with serologic testing (26.7% vs. 17.2%). Limitations: The novel methodology requires external validation. Case and testing data were not linkable at the individual level. Conclusion: Adjustment for testing frequency provides a different picture of SARS-CoV-2 infection risk by age, suggesting that younger males are an underrecognized group at high risk for SARS-CoV-2 infection. Primary Funding Source: Canadian Institutes of Health Research.
- Subjects :
- Adult
Male
medicine.medical_specialty
Adolescent
Coronavirus disease 2019 (COVID-19)
Population
Negative binomial distribution
Standardized test
Young Adult
Age Distribution
COVID-19 Testing
Linear regression
Internal Medicine
Humans
Medicine
Differential testing
Sex Distribution
Young adult
Child
education
Pandemics
Aged
Aged, 80 and over
Ontario
education.field_of_study
SARS-CoV-2
business.industry
Incidence
Public health
Incidence (epidemiology)
Infant, Newborn
COVID-19
Infant
General Medicine
Middle Aged
Test (assessment)
Binomial Distribution
Child, Preschool
Research and Reporting Methods
Female
business
Demography
Cohort study
Subjects
Details
- ISSN :
- 15393704 and 00034819
- Volume :
- 174
- Database :
- OpenAIRE
- Journal :
- Annals of Internal Medicine
- Accession number :
- edsair.doi.dedup.....099d3c695ee7499f2051421eac0092ea