Millions of women across the UK use oral contraceptives. This study drew on data gathered over a 29 year period and demonstrated that women who have used the pill do not have an increased risk of death.

Why was this work needed?

The contraceptive pill is the most commonly used form of contraception in the UK and has been in widespread use since it first became available in 1961. Early reports into the safety of the pill suggested that it was associated with an increased rate of death. Given the large number of women using it, it is very important that we have an accurate sense of any risks involved with its use.

What happened?

Although this research was conducted in 2010, it used data that was collected between 1968 and 1996, via the RCGP Oral Contraception Study. In 1968, 1,400 general practitioners throughout the United Kingdom recruited approximately 23,000 women who were using oral contraceptives and a similar number of women who had never used them.

Researchers then used data from these women to assess any links between oral contraceptive use and death. A key strength of this study was that researchers had access to almost thirty years of data, allowing them to assess the impact of contraceptive use on an entire population.

What were the benefits?

This research demonstrated that there was not a substantial increase in death rates for women who used oral contraceptives and that, in this cohort, mortality was lower among women who had used the pill.

What type of data was involved?

The data involved is primarily from the GP surgeries that took part, although some data (cancer diagnosis and deaths) comes from central NHS data sources. The age of the study means that the data sources are not directly comparable to those used now.

GPs recruited women to take part in this study.

The study was established before the introduction of research ethics committees in the UK. Even so, procedures were used to maintain the confidentiality of women. Correspondence between participating doctors and the study, and between the NHS central registries and the study, used a unique study number, the key to which only the GPs knew.

Who funded and collaborated on this work?

This study received funding from the Royal College of General Practitioners, the Medical Research Council, Imperial Cancer Research Fund, British Heart Foundation, Cruden Foundation, Schering AG, Schering Health Care, Wyeth Ayerst International, Ortho Cilag, and Searle.

Where can I go for more information?

Mortality among contraceptive pill users: cohort evidence from Royal College of General Practitioners’ Oral Contraception Study