Determinants of SARS-CoV-2 nasopharyngeal testing in a rural community sample susceptible of first infection: the CHRIS COVID-19 study

ABSTRACT

To characterize COVID-19 epidemiology, numerous population-based studies have been undertaken to model the risk of SARS-CoV-2 infection. Less is known about what may drive the probability to undergo testing. Understanding how much testing is driven by contextual or individual conditions is important to delineate the role of individual behavior and to shape public health interventions and resource allocation. In the Val Venosta/Vinschgau district (South Tyrol, Italy), we conducted a population-representative longitudinal study on 697 individuals susceptible to first infection who completed 4,512 repeated online questionnaires at four-week intervals between September 2020 and May 2021. Mixed-effects logistic regression models were fitted to investigate associations of self-reported SARS-CoV-2 testing with individual characteristics (social, demographic, and biological) and contextual determinants. Testing was associated with month of reporting, reflecting the timing of both the pandemic intensity and public health interventions, COVID-19-related symptoms (odds ratio, OR:8.26; 95% confidence interval, CI:6.04–11.31), contacts with infected individuals within home (OR:7.47, 95%CI:3.81–14.62) or outside home (OR:9.87, 95%CI:5.78–16.85), and being retired (OR:0.50, 95%CI:0.34–0.73). Symptoms and next within- and outside-home contacts were the leading determinants of swab testing predisposition in the most acute phase of the pandemics. Testing was not associated with age, sex, education, comorbidities, or lifestyle factors. In the study area, contextual determinants reflecting the course of the pandemic were predominant compared to individual sociodemographic characteristics in explaining the SARS-CoV-2 probability of testing. Decision makers should evaluate whether the intended target groups were correctly prioritized by the testing campaign.

KEYWORDS:

• SARS-CoV-2
• COVID-19
• PCR
• swab
• testing
• cooperative health research in south tyrol

Acknowledgements

We are grateful to all CHRIS COVID-19 study participants. We thank the collaborators of both Eurac Research and the Healthcare System of the Autonomous Province of Bolzano for field and laboratory operations, the representatives and staff of the local Administrative Authorities for support and all ancillary volunteers who eventually made the study possible. The authors thank the Department of Innovation, Research and University of the Autonomous Province of Bozen/Bolzano for covering the Open Access publication costs (unique project code: B57G23000270003).

Disclosure statement

No potential conflict of interest was reported by the authors.

Authors’ contributions

CP, PPP, RM, and MG conceived the CHRIS COVID-19 study.

CP and DG conceived the investigation topic object of the present work.

DG, GB, MG, and DB performed the statistical analyses.

DG, GB, MG, DB, LF, CXW, RM and CP interpreted the results.

DG, RM, and CP drafted the manuscript.

LF, LB, RL, DB, RM, MG, CXW, PP contributed to the critical revision and editing of the manuscript.

Data availability statement

Given national legal restrictions for the publication of health data, the Institute for Biomedicine developed an access policy compliant to it. The data used for this work can be obtained by submitting a substantiated request to the CHRIS Access Committee at [email protected].

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/20477724.2023.2191232.

Additional information

Funding

The CHRIS COVID-19 study was supported by Eurac Research, the South Tyrolean Health Authority, and the Department of Innovation, Research and University of the Autonomous Province of Bolzano. The present research was conducted within the project ‘PACE: Partnership to Accelerate COVID-19 rEsearch in South Tyrol’, funded by Department of Innovation, Research and University of the Autonomous Province of Bolzano within the 2019–2021 Research Program (unique project code: D52F20000770003). Funding sources did not have any role in the research conduction, writing of the manuscript, and decision to submit it for publication. Authors were not precluded from accessing data in the study, and they accept responsibility to submit for publication.