BMC Medical Research Methodology (May 2024)

CalScope: methodology and lessons learned for conducting a remote statewide SARS-CoV-2 seroprevalence study in California using an at-home dried blood spot collection kit and online survey

  • Esther Lim,
  • Megha L. Mehrotra,
  • Katherine Lamba,
  • Amanda Kamali,
  • Kristina W. Lai,
  • Erika Meza,
  • Stephanie Bertsch-Merbach,
  • Irvin Szeto,
  • Catherine Ley,
  • Andrew B. Martin,
  • Julie Parsonnet,
  • Peter Robinson,
  • David Gebhart,
  • Noemi Fonseca,
  • Cheng-ting Tsai,
  • David Seftel,
  • Allyx Nicolici,
  • David Melton,
  • Seema Jain

DOI
https://doi.org/10.1186/s12874-024-02245-y
Journal volume & issue
Vol. 24, no. 1
pp. 1 – 10

Abstract

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Abstract Background To describe the methodology for conducting the CalScope study, a remote, population-based survey launched by the California Department of Public Health (CDPH) to estimate SARS-CoV-2 seroprevalence and understand COVID-19 disease burden in California. Methods Between April 2021 and August 2022, 666,857 randomly selected households were invited by mail to complete an online survey and at-home test kit for up to one adult and one child. A gift card was given for each completed survey and test kit. Multiple customized REDCap databases were used to create a data system which provided task automation and scalable data management through API integrations. Support infrastructure was developed to manage follow-up for participant questions and a communications plan was used for outreach through local partners. Results Across 3 waves, 32,671 out of 666,857 (4.9%) households registered, 6.3% by phone using an interactive voice response (IVR) system and 95.7% in English. Overall, 25,488 (78.0%) households completed surveys, while 23,396 (71.6%) households returned blood samples for testing. Support requests (n = 5,807) received through the web-based form (36.3%), by email (34.1%), and voicemail (29.7%) were mostly concerned with the test kit (31.6%), test result (26.8%), and gift card (21.3%). Conclusions Ensuring a well-integrated and scalable data system, responsive support infrastructure for participant follow-up, and appropriate academic and local health department partnerships for study management and communication allowed for successful rollout of a large population-based survey. Remote data collection utilizing online surveys and at-home test kits can complement routine surveillance data for a state health department.

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