Quality assurance follow-up survey of the ELISA cohort study on the prevalence of COVID-19: The view of study participants - What is well received?

Introduction: With the outbreak of the Corona pandemic, the LubEcker longitudinal study on infections with SARS-CoV-2 (ELISA study) was conducted in the Lubeck area to provide information on the prevalence, unreported cases and symptoms of COVID-19. The aim of the present study is to evaluate defined structure and process indictors of the study conduct of the ELISA study by subjects. Methods: After defining and operationalizing participant-oriented quality indicators, 3,710 participants were surveyed online via LimeSurvey. Indicators defined were access to the study, time requirements, reporting of findings, ratings of the study apps used, communication, study center, tolerability of sample collection, and willingness to re-participate. In addition, comments on push and pull factors of study participation could be made. The evaluation was both quantitative and qualitative. Results: 45% of the follow-up respondents (n = 1,684) answered the questions on the defined structural and process indicators. In the quantitative part of the survey, tolerability of venous blood sampling was rated as significantly better than that of nasopharyngeal smears. 91% of the follow-up respondents welcomed the offer to view their findings in the personal results portal. Overall, the indicators were mostly rated positively. According to the qualitative data, the study participants found the win-win situation of the test opportunity to contribute to research, the local relevance of the study, the small incentives, and the low-threshold nature of the study registration to be positive aspects of the study. According to the quantitative data, participants suggested improving the usability of the digital applications in terms of more user-friendly identification solutions, reminder functions, announcements of software updates and avoidance of double entries. Discussion: The defined structure and process indicators appear to be suitable for assessing the quality of study implementation from the subjects' point of view and indicate a good quality of study implementation under pandemic conditions. The lowest participation rate (75%) was measured at the fifth test time of strongly declining COVID-19 infections during the summer holidays in Schleswig-Holstein. Obviously, the benefit and meaningfulness of further study participation as well as competing factors were weighted differently by the subjects at this point. The follow-up survey suggests a variety of options for motivating participants to maintain a high level of participation. Possible limitations are that a non-response bias cannot be excluded for the follow-up survey and that no suitable standardised questionnaire was available. Conclusion: The present study provides recommendations for the planning of future cohort studies. It makes sense to continuously evaluate the motives for participation or non-participation and to explicitly consider them in the course of the study. Therefore, the definition of general quality indicators for the practical implementation of studies seems desirable. Positive experiences of the participants in connection with study participation are important, such as good time management, short response times, technical support offers and additional services such as a study homepage with frequently asked questions (FAQs), timely individual notifications of results and transparent, generally understandable information about study results during the study. Digital solutions are well received, but can still be improved for specific studies.