The project is being managed by a multi-disciplinary team of researchers from University College London (UCL), the London School of Hygiene & Tropical Medicine (LSHTM), the University of Glasgow and NatCen Social Research (NatCen).

The Natsal Resource (including Natsal-4) is supported by a grant from the Wellcome Trust with contributions from the Economic and Social Research Council and the National Institute of Health Research.


Covid-19 Update:

Following Natsal-4 development work, the next stage for Natsal-4 is a fieldwork pilot, which, due to COVID-19, has been postponed (previously planned for May 2020, but now currently scheduled for summer 2021).

As a result of the COVID-19 pandemic, the study is likely to require further review before piloting to ensure it is fit-for-purpose. Some reprioritisation, expansion, or new topics may be required to reflect recent changes in sexual behaviour, relationships, and access to services. Any such changes to the questionnaire and its delivery will be based on both further engagement with stakeholders, and results of our own and others’ empirical work around the impacts of the pandemic.


How did you decide on the study design for Natsal-4?

We undertook a Scoping Review to consider the most appropriate methodological approach for Natsal-4. This review assessed methods used to date by other major UK population surveys and by population surveys of sexual health internationally. The review distinguished between sampling methods and recruitment/data collection mode (e.g. face-to-face, web, telephone) as each have distinct implications for data quality and resource.

The findings have been published as a scoping review and also published as an Editorial in the journal, Sexually Transmitted Infections.



What's planned for Natsal-4?

The fourth Natsal survey will interview over 9,000 people aged 16-59 years. Survey answers will be combined with information from biological samples (e.g. urine to test for sexually transmitted infections) and routinely collected data (e.g. health records). We will oversample (‘boost’) young people and people from black African and black Caribbean groups to allow more detailed statistical analyses of these groups.

Why has this age range been chosen?

The age range covered by Natsal has varied with each survey round. Although we wanted to include people over 59 years in Natsal-4, there were limited resources available and this was one of the difficult decisions we had to make. Natsal-3, which included people aged 16-74 years, focused on how people’s experiences vary throughout their lives.  Natsal-4 will focus more on young people, including oversampling 16-35 year olds so that we can better understand variation within this age group. This is because young people experience the greatest social and sexual changes and are more likely to experience adverse sexual health outcomes than other groups.

Why are you boosting the numbers from black Caribbean and black African backgrounds?

Even with a sample size of around 9,000, we would not usually interview enough people from these groups to be able to analyse them separately. For this reason, in Natsal-3 we often had to group non-white ethnic groups together in analysis. Compared with people from other ethnic groups, people of black African ethnicity are disproportionately affected by HIV, and people of black Caribbean ethnicity are more likely to be diagnosed with some STIs or experience teenage pregnancy. This is why we have decided to boost the number of people we interview from these groups, so that they can be represented in the study’s findings. Unfortunately, this kind of boost sample is resource intensive, and so we have not been able to oversample other ethnic minority groups.

What biological samples will Natsal-4 collect and what will they be used for?

We will invite men and women to provide samples to test for sexually transmitted infections (STIs) (Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, and for women only Human Papillomavirus (HPV)). These will be urine samples for men, and for women we will explore the feasibility of self-collected vulvo-vaginal swabs because these allow more accurate testing. We will assess the feasibility of returning clinically relevant results to participants using an online NHS results service. The biological samples will be stored in a biobank so that they can be used for future research. For example, the samples could be tested for the microbiota, which are the groups of microorganisms which inhabit our bodies: some are beneficial, but others may cause illness.

What routinely collected data will you use?

All Natsal-4 participants will be invited to consent to link their survey and biological data to their health records and other routinely-collected data. Linking these records creates opportunities to expand the range of data we have to answer complex research questions in ways that have not previously been possible.

Natsal Stakeholder consultation

The Natsal Team held an open online consultation to get your views on the questions that should be asked in Natsal-4, which began on 1 May 2019.

Natsal-4 builds upon over 30 years of research into the sexual health and wellbeing of the British population, leading to major impacts on policy, practice, and the public dialogue about sex, as well as advancing - nationally and internationally - the scientific study of this critical area of our lives.

The Natsal team held an open consultation between 30th June 2019 and 28th July 2019 to capture the views of stakeholders and interested members of the public on the content of the Natsal-4 questionnaire.

Stakeholder consultation responses

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.

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.

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