Dialogue: Time to come clean on the pill

CHARLOTTE PAUL* wonders why influential medical groups in this country are so against publicising the rare risks of the pill.

The Abortion Supervisory Committee has just released its report to Parliament showing a rise in abortions in 1999, predicting a rise last year, and blaming pill scares as a major factor in the increase.

The only evidence it gives for this is a report by Dr Felicity Goodyear-Smith and Dr Bruce Arroll. The study on which the report was based was published in the New Zealand Family Physician in October. It is unconvincing.

The doctors reviewed the case notes of 400 women attending one clinic in mid-1999 and found that 9.5 per cent of those women reported panic stopping of oral contraceptives. No further details on the reasons for stopping are given. It is unconvincing because there is no comparison, and because asking women their reasons for having an unwanted pregnancy is likely to elicit socially acceptable responses.

Longer-term trends published in the Abortion Supervisory Committee report show a general inexorable rise in abortion numbers, from 5945 in 1980 to 11,170 in 1990 to 15,501 in 1999.

A more detailed look at abortion rates by age groups shows that from 1996 there has been no increase in abortion rates among teenagers, the group thought most vulnerable to pill scares, while rates in all other age groups increased.

Transient effects of pill scares are harder to find, and require information on monthly abortion rates. No such effects have been demonstrated in New Zealand.

With no good evidence that there is a relationship between abortion rates and pill scares in this country, why have groups like the Medical Association and the Family Planning Association been so critical of publicity about rare risks of the pill?

The risks in question are of venous thromboembolism blood clots in the leg that may affect the lungs. They can occur with any combined oral contraceptives, but have been shown to be less rare with third-generation pills. Since 1996, Medsafe, in the Ministry of Health, has advised doctors to consider prescribing second-generation pills for new users.

Practising doctors say they are concerned because they have had worried patients attending and asking to change their pills from third-generation to the safer second-generation pills, or to stop the pill altogether. But, surely, for women to reduce their risks in these ways makes sense?

There is little evidence of other differences in side-effects between third- and second-generation pills for most women, and there are other contraceptive choices available. The publicity, even if over the top, has at least alerted women to these risks and empowered them to do something about them.

But I don't think the reason for the concern of these groups is just that some media coverage has been irresponsible. The New Zealand media is generally much more careful than the tabloid press in Britain, where there was a measurable increase in abortions. It must be because these influential groups simply do not accept the evidence about the increase in risk.

Both the clinical spokeswoman for the Family Planning Association, Dr Christine Roke, and the New Zealand committee of the Australian and New Zealand College of Obstetricians and Gynaecologists have written to the Medical Journal in the past 12 months asserting that third-generation pills do not carry a greater risk of venous thrombosis than second-generation pills.

Last June, the Lancet published results of a New Zealand study of deaths from pulmonary embolism in women. This showed that the risk of death from pulmonary embolism with pill use was higher than previously reported. The risk was also higher with third-generation pills, compared with second-generation pills, consistent with many other independent studies in Europe.

After this, Dr Pippa MacKay, who chairs the Medical Association, was quoted as suggesting that the only studies finding this higher risk were from New Zealand, when, in fact, this has been the only New Zealand study.

She asked how it was that New Zealand still seemed to persist in the belief that there was something different. Was it something different about our women or our studies?

At the same time, Dr MacKay devoted a whole issue of the association newsletter to a confusing debate on the subject. She began by publicising a study apparently showing that, despite a decline in the use of third-generation pills in Britain, the decline in venous thromboembolism was less than expected.

She concluded the piece by quoting the assertion of Dr Christine Roke, of Family Planning, of no difference in risk.

Unfortunately, these groups are not taking an unbiased look at the evidence. That British study has now been superseded by a better-designed analysis using the same database, which showed that there had, indeed, been a drop in incidence of venous thromboembolism.

Moreover, the editor of the British Medical Journal made a formal apology for the journal's handling of the first paper, and raised concerns about the age-adjustment used in it.

An accompanying editorial by Professor David Skegg called for a thorough investigation by Britain's Medicines Control Agency.

These latest developments were highly newsworthy, but none of the medical groups I have mentioned publicised the story. The views publicised by these influential groups are seriously at odds with independent assessments made by the New Zealand expert committee - the Medicines Adverse Reactions Committee.

For the sake of their public credibility, it is time for these groups to stop and look carefully at any new evidence which seems to support their claim of no increased risk with third-generation pills.

If they publicise such evidence without due consideration, they run the risk of allowing the use of third-generation pills to rise again in New Zealand.

This could lead to an increase in the rate of disability and death from this rare condition for no good reason.

* Dr Charlotte Paul lectures in Otago Medical School's department of preventive and social medicine.