Why did Natsal start?
Natsal was launched in the mid-1980s in response to the emerging HIV epidemic, with the aim of providing reliable information on the sexual behaviours and attitudes of people living in Britain at the time. Interviews for the first survey, involving participants aged 18-59 began in 1990 following a successful pilot study, which demonstrated that a vast majority of people in Britain were comfortable participating in scientific research on sexual health and behaviour, despite widespread scepticism.
In fact, the first Natsal study almost never happened. Although Natsal was due to receive public funding, the then Prime Minister, Margaret Thatcher, withdrew support at the last minute, expressing concern that the survey was an invasion of people’s privacy. Fortunately, the Wellcome Trust stepped in and, following a rapid independent review, agreed to fund the research in 1990.
The results had a far greater impact than the research team had initially envisaged, going on to shape sexual and reproductive healthcare and policy far beyond HIV/AIDS.
Access the full Natsal-1 questionnaire and dataset here.
Watch the remarkable story behind Natsal’s origins and its lasting impact through the reflections of Anne Johnson, co-founder of the first Natsal study:
What has changed since Natsal-1?
Natsal-2 took place between 1999-2001 in response to growing demand in the mid-1990s for up-to-date information on sexual health and behaviour in Britain. Whilst Natsal-2 had a narrower target age-range (16-44 years), it’s focus was broader than Natsal-1. Monitoring HIV/AIDS and examining patterns of sexual behaviour remained an important focus of the study.
Natsal-2 also looked at pregnancy experiences and STI prevalence in the population using both self-reported survey data on behaviours and collecting urine samples to test for Chlamydia, one of the most common STIs at the time. Evidence generated by Natsal-2 was used to inform STI screening policy and the delivery of sexual health services. Access the full Natsal-2 questionnaire and dataset here.
Natsal-3 was undertaken between 2010-2012 to provide updated data on sexual health in Britain. These data enabled comparison over time and demonstrated some evidence of change, although not to the same extent as observed between Natsal-1 and Natsal-2.
A unique feature of Natsal-3 was the extended age range of participants, including people from aged 16 to 74, providing a more comprehensive picture of sexual experiences across the life course. The survey also differed from previous Natsal studies by expanding the definition of sexual health to include questions on sexual function and well as non-volitional sex (sexual experiences that are unwanted or involuntary). Access the full Natsal-3 questionnaire and dataset here.
As with Natsal-2, participants were asked to provide urine samples, but testing was expanded to include five STIs. In Natsal-3, saliva samples were also collected to measure testosterone levels and examine their association with both general and sexual health.
Natsal-4 was carried out between September 2022 to April 2024 and achieved a total sample of approximately 19,000 people aged 16-59, using a combination of sampling and data collection methods. The Natsal-4 survey incorporates several new developments to reflect the significant individual, societal and technological changes that have taken place since Natsal-3.
The age range covered by Natsal has evolved across survey rounds, from 16-59 years in Natsal-1, to 16-44 years in Natsal-2, widening to 16-74 years in Natsal-3. These changes reflected the specific aims of each study, the availability of complementary evidence, and the funding available at the time. For more information on the age range, read about the development work for Natsal-4 here.
For more information on the history of Natsal, watch this BBC2, Horizon Special documentary from 1992:
Further resources: