How did you decide on the study design for Natsal-4?
The original design for Natsal-4 was an address-based probability sample of 10,000 people, informed by a 2019 Scoping Review and due to take place in 2020. However, due to the impact of the COVID-19 pandemic on participation in surveys in Britain and internationally, the design was adapted to use multiple sampling strategies and modes of data collection (‘fieldwork arms’), including the original address-based probability sample (face-to-face and telephone interviews), a probability panel (telephone and online) and a non-probability panel (online). For more details of the different arms see ‘Natsal-4 Data Collection Overview’.
The findings have been published as a scoping review and also published as an Editorial in the journal, Sexually Transmitted Infections.
Why was this age range chosen?
We recognise that sex and sexuality are relevant throughout the life course and so are independent of age. However, the age range covered by Natsal has varied with each survey round, initially 16-59 years for Natsal-1, shrinking to 16-44 years for Natsal-2, widening to 16-74 years for Natsal-3, reflecting the different research objectives for each round, availability of complementary evidence, and, as with all projects, funding available. For example, Natsal-3’s broad age range enabled us to examine how people’s experiences vary throughout their lives. After careful consideration, we decided to make the age range for Natsal-4 16-59 years, in part reflecting how the English Longitudinal Study of Ageing (ELSA) has collected information on sex and relationships from older adults, including those living in institutions. Natsal-4 instead focused on young people, including oversampling 16-29 year olds, so that we can better understand variation within this age group because young people experience the greatest social and sexual changes and are more likely to experience adverse sexual health outcomes than other age groups.
Cognitive testing report
For those interested in the cognitive testing of new and revised questions, which followed our stakeholder consultation and review process, you can download and read NatCen’s cognitive testing report.
Stakeholder consultation on the questionnaire topics
The Natsal team held an open consultation in June/July 2019 to capture the views of stakeholders and interested members of the public on the content of the Natsal-4 questionnaire.
We received 294 responses (online and via email); 30 from organisations and 264 from individuals including members of the public, researchers, clinicians, policy makers, educators, and those representing voluntary or community groups.
In addition to commenting on topics that consultees thought should be added or removed, consultees were asked to rank the importance of topics which have been included in the previous Natsal surveys, and new topics planned for Natsal-4. The five highest ranking topics were: ‘Experience of sex against your will’, ‘Gender identity’, ‘Sexual attraction, experience and identity’, and ‘Use of sexual health services and testing’ .
Consultees proposed many new topics and specific questions they thought to be relevant for Natsal-4, and there were relatively few suggestions for topics to remove from the existing questionnaire.
The consultation responses fed into a series of prioritisation exercises (undertaken August-September 2019) to determine which questions would be taken forward as part of the questionnaire for the Natsal-4 pilot study. This was necessary due to restrictions on the overall feasible questionnaire length (under 1 hour) against the large number of potential new topics and questions and the need to retain many questions from previous surveys.
Consultees also proposed improvements to existing questions, which fed into a wider questionnaire design review. Decisions about which changes to make balanced the need to make improvements to the existing questionnaire (some sections were initially developed in the late 1980s) with the need to keep core question wording the same to enable examination of change over time.
For each section of the questionnaire, a summarised version of consultees’ comments and the corresponding decisions is provided in section 6.3 of our full report.