The effects on mortality of the use of combined oral contraceptives.

OBJECTIVE

To assess, using a computerised model, the effects on mortality of the use of combined oral contraceptives (COCs).

DESIGN

Two hypothetical cohorts of one million women each, identical except for their use of contraception. The impact of COC use was explored by applying, to each cohort, death rates which were adjusted according to a series of assumptions about the risks associated with COC use. The model also explored the effects of a number of different patterns of COC use.

SETTINGS AND SUBJECTS

Women aged 16, followed through to ages 50 and 75, exposed to 1994 UK death rates.

MAIN OUTCOME MEASURES

Numbers of deaths from various cancers and cardiovascular diseases attributable to COC use.

RESULTS

Based on the standard pattern of use, there were 1.7 per cent more deaths in the COC cohort to age 50. The important effects on mortality of different patterns of use and of different assumptions about risks in ex-users were illustrated.

CONCLUSIONS

The results confirm the findings of earlier work and provide some reassurance about the likely adverse effects of COC use.