Table 1 Most common reasons for non-participation stated in the tick boxes and the free text field of the invitation letter
First surveillance round: | |||
Reasons | Number of Counts | Percentage of 207 stated reasons | |
Tick Answers | Did not want to undergo saliva sampling | 42 | 20.29% |
Did not want to spend as much time on the topic | 26 | 12.56% | |
Data privacy concerns | 25 | 12.08% | |
Did not think the topic was important | 6 | 2.90% | |
Free text field answers | Medical and health issues (not associated with COVID-19) | 21 | 10.14% |
High age | 13 | 6.28% | |
Longer stay outside Cologne | 10 | 4.83% | |
Taking regular tests for SARS-CoV-2 infection | 9 | 4.35% | |
No access to internet / No technical equipment | 8 | 3.86% | |
Too much effort | 8 | 3.86% | |
General criticism of the study | 8 | 3.86% | |
Already vaccinated | 6 | 2.90% | |
Second surveillance round: | |||
Reasons | Number of Counts | Percentage of 96 stated reasons | |
Tick Answers | Did not want to undergo saliva sampling | 15 | 15.63% |
Did not want to spend as much time on the topic | 12 | 12.50% | |
Data privacy concerns | 7 | 7.29 | |
Did not think the topic was important | 3 | 3.13% | |
Free text field answers | Medical and health issues (not associated with COVID-19) | 12 | 12.50% |
Already vaccinated | 10 | 10.42% | |
Longer stay outside Cologne | 8 | 8.33% | |
Personal reasons | 4 | 4.17% | |
Missed deadline for participation | 4 | 4.17% | |
High age | 3 | 3.13% | |
No access to internet/No technical equipment | 3 | 3.13% | |
No acceptance of gender-sensitive language | 3 | 3.13% | |