CIS survey of questions on vaccination status

FOI REF: FOI-2024-1988

You asked

Please provide the survey wording for the questionnaire used to produce "Self-reported coronavirus (COVID-19) infections and associated symptoms, England and Scotland: November 2023 to March 2024." 

Please provide the survey wording for the questionnaire used to produce "Self-reported long COVID after two doses of a coronavirus (COVID-19) vaccine in the UK: 26 January 2022." 

Please provide all email correspondence relating to discussions of the wording in the survey of questions around vaccination status. 

We said

Thank you for your request.

The COVID-19 Infection Survey (CIS) launched in the height of the pandemic. Over time, additional questions were added to the survey to better understand long COVID. In January 2022, we published the following analysis: Self-reported long COVID-19 after 2 doses of a COVID-19 vaccination. In summary, this article examined odds ratios for symptoms reported at least 12 weeks after coronavirus (COVID-19) infection, comparing  CIS participants who had received two doses of a COVID-19 vaccine before infection with those who were unvaccinated.

The survey questions asked of respondents to produce this analysis can be found via the following link: https://www.ndm.ox.ac.uk/covid-19/covid-19-infection-survey/case-record-forms. Version 14 of the questionnaire was the version used to produce the report.

The questions included in the CIS were developed at pace following the ‘lockdown’ of March 2020. As can be seen throughout the 14 versions of the questionnaire (accessible through the above link), question design changed as the ONS explored the data around COVID-19. In section F, COVID-19 Infection and You, for instance, questions that asked about symptoms went through several iterations where the list of symptoms was expanded as medics and scientists understood more about the infection process. With regard the question concerning COVID-19 vaccination in section F, this first appeared in questionnaire version seven, with a binary question designed to capture whether or not a person had been vaccinated. Subsequent versions of the questionnaire then added further detail around number of vaccinations or booster vaccinations and asked for more information about which COVID-19 vaccination variant participants received. The only change to the core question (“Have you been vaccinated against COVID-19?”) across the variations of the questionnaire was the addition of the word “ever” (“Have you ever been vaccinated against COVID-19?).

This change was discussed across the CIS team, including the Principal Investigator, and the word “ever” added to ensure participants answered “yes” to this question even if they had not had a vaccine in the month between study visits. In the data, we noted that some participants would tick “no” this question despite having ticked “yes” previously due to the slight ambiguity of the question. Adding “ever” ensured this did not happen subsequently.

It should also be noted that every change made to any part of the study was reviewed and approved by the National Health Services’ Integrated Research Application System (NHS IRAS) and the Research Ethics Committee (REC). The IRAS and REC are completely independent of the Civil Service and the ONS and review all studies that involve NHS patients, among others. By obtaining permission from IRAS and REC, the CIS had ethical approval to conduct the study. Included at every ethical review were the questionnaire, any paperwork that participants received, and the study protocol itself (the document that states exactly what the ONS and its partners were permitted to do as part of the study). Part of the approval process required the ONS to publish its questionnaires in full, all of which can be accessed at the above link.

The Winter Covid Infection Study (WCIS) was launched jointly by the ONS and the UK Health Security Agency in 2023, with data collected by the ONS via online questionnaire completion and self-reported Lateral Flow Device (LFD) results. As part of our analysis plan, we produced the following findings.

This article expanded on the existing analysis published in the fortnightly WCIS data tables to look more in depth at trends in self-reported symptoms of COVID-19, including ongoing symptoms and associated risk factors.

The survey questions asked of respondents to produce this analysis can be found in the associated download named ‘Winter_CIS_Main_Questionnaire’.

As explained above, the survey design involved numerous email exchanges between several internal and external colleagues handling multiple issues concurrently. Email history for the survey design is therefore incredibly complex and not easily interrogated.

Owing to the range of issues discussed in email exchanges at the time, we cannot be confident that key-word searches (such as COVID-19 vaccine, CIS design, etc) would pick up every email exchanged on the requested topic. In addition, these key word searches alone have returned 1000s of emails, all of which would need to be interrogated to assess whether they are in scope.

The cost limit for Freedom of Information requests is £600, which equates to 24 working hours. The search for, location, extraction, and collation of the information requested would be greatly exceeded by actioning this request. Therefore, Section 12 of the Freedom of Information Act 2000 (FOIA) applies.

If you have any queries following the information provided in our response, please get back in touch.