About the study

history

The Million Women Study was founded by Professor Dame Valerie Beral, Professor Emily Banks and Julietta Patnick. Valerie Beral was the Chief Investigator of the study until 2020 and, upon retirement, remained as one of the principal investigators until her death in August 2022.

In order to investigate the effects of medications (such as menopausal hormones) and behaviours (such as smoking, alcohol drinking and physical activity) on the risk of women developing diseases, the study needed to have detailed information from women on their lives and information from women’s health records.

study description

The Million Women Study is a population-based open-ended ongoing prospective cohort study. In 1996 around 1.3 million UK women aged 50-64 were recruited into the study at the time that they were invited for routine breast screening. Participants completed a postal questionnaire at recruitment which asked about sociodemographic, lifestyle and other personal characteristics, and women have since been re-surveyed every three to five years to update information on key factors, and to collect information on new risk factors of interest. Information has also been collected for subsets of participants through additional postal and online questionnaires, for example for diet and daily activities. The study was one of the first to establish linkage to NHS records in order to follow participants up for major health outcomes including cancers, hospital admissions and deaths, and the study continues to expand its linkages to include other routinely collected health-related outcomes in order to address emerging research questions.

Since 2006, around 5% of participants have also provided a blood or saliva sample as part of a related study, the Million Women Study: Disease Susceptibility Study. More recently, a small number of participants were invited to take part in the Changes to Lifestyle in Retirement Study. Read more about these related studies.

The Million Women Study cohort profile provides a full description of the study.

collaborators

We gratefully acknowledge the contribution of staff at the collaborating NHS Breast Screening Centres involved in the recruitment and breast screening for the study. Participants were recruited in the following NHS Breast Screening Centres during the period 1996-2001:

Avon, Aylesbury, Barnsley, Basingstoke, Bedfordshire and Hertfordshire, Cambridge and Huntingdon, Chelmsford and Colchester, Chester, Cornwall, Crewe, Cumbria, Doncaster, Dorset, East Berkshire, East Cheshire, East Devon, East of Scotland, East Suffolk, East Sussex, Gateshead, Gloucestershire, Great Yarmouth, Hereford and Worcester, Kent, Kings Lynn, Leicestershire, Liverpool, Manchester, Milton Keynes, Newcastle, North Birmingham, North East Scotland, North Lancashire, North Middlesex, North Nottingham, North of Scotland, North Tees, North Yorkshire, Nottingham, Oxford, Portsmouth, Rotherham, Sheffield, Shropshire, Somerset, South Birmingham, South East Scotland, South East Staffordshire, South Derbyshire, South Essex, South Lancashire, South West Scotland, Surrey, Warrington Halton St Helens and Knowsley, Warwickshire Solihull and Coventry, West Berkshire, West Devon, West London, West Suffolk, West Sussex, Wiltshire, Winchester, Wirral, Wycombe.

advisory committee

Emily Banks, Lucy Carpenter, Carol Dezateux (Chair), Sarah Floud, Jane Green, Julietta Patnick, Richard Peto, Gillian Reeves, Cathie Sudlow.

funders

The Million Women Study Coordinating Centre is based in the Cancer Epidemiology Unit, part of Oxford Population Health. The study was set up in collaboration with the NHS Breast Screening Programme and has received funding from these organisations:

• Cancer Research UK has an extensive range of online cancer-related resources for patients, researchers and clinicians and includes links to other cancer organisations. 
• The Medical Research Council has information about current research projects.
•  Health and Safety Executive.