The Million Women Study

Aims
The Million Women Study is a population-based cohort study of 1.3 million women born in 1935-1950 with the aim of providing reliable information on potentially modifiable causes of common and serious illnesses. Participants’ health has been followed mainly through linkage to routinely collected NHS records as well as re-surveys. Current focus is on risk factors for cancer, dementia, osteoporosis, stroke and other severe disabling conditions that become increasingly common as women age.

Institution
Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford

Geographic coverage - Nations
England, Scotland

Geographic coverage - Regions
Nationwide

Start date
1996

Catalogue record last updated
25/09/2024

Sample type
Cohort study

Sample details
The NHS Breast Screening Programme invites all UK women registered with the NHS, of a specified age, for free routine breast screening every 3 years. In 1996–2001 the programme routinely invited women aged 50–64 years for mammographic screening, by sending each individual a letter offering them a specific date and time at a specific screening centre. In 66 NHS screening centres, the Million Women Study recruitment questionnaire was included with the invitation letter for screening. The cohort included 1.32 million women without previous cancer and includes women with a wide range of backgrounds, behaviours and lifestyles broadly similar to those of all UK women of their age.

Sample size at recruitment
1,319,475

Sample size at most recent sweep
837,985 (2005 - 3-year re-survey)

Sex
Women only

Age at recruitment
50-64 years

Cohort year of birth
1935-50