Competing interests and controversy about third generation oral contraceptives. BMJ readers should know whose words they read.
Year: 2000
Type: article
Abstract: Editor—The influence of competing interests arising from funding by the pharmaceutical industry is worrying in the controversy about third generation oral contraceptives.1 At the end of 1998 three major studies without sponsoring from the industry found a higher risk of venous thrombosis for third generation contraceptives, unlike three sponsored studies.2 To date, of nine studies without sponsoring, one study found no difference and the other eight found relative risks from 1.5 to 4.0 (summary relative risk 2.4); four sponsored studies found relative risks between 0.8 and 1.5 (summary relative risk 1.1) (references available on the BMJ's website, www.bmj.com). The sponsored study with a relative risk of 1.5 has been reanalysed several times, yielding lower relative risks; after this failed to convince,3 a new reanalysis was sponsored by another company.4
In 1995 four studies found the same risk. That evidence was sufficient for public health action since equally reliable pills were available. For at least one company the third generation pill secured more than half its revenue. The companies proclaimed that with almost total certainty everything was the result of bias and confounding. Even for a sceptic at the time, that was an unreasonable position: all four studies were reasonably executed and had withstood criticism from the Committee on Safety of Medicines and reviewers of leading journals. Thus, the companies' position ran the high risk ofdamaging both their product and their credibility. Their behaviour is reminiscent of that described by Barbara Tuchman in 1984 in The March of Folly: from Troy to Vietnam, in which rulers become removed from reality and continuously act against their own best interests despite clear warnings.
Since 1995 three multinational companies have used enormous marketing resources to sow confusion. An avalanche of special symposia and paid supplements convinced outsiders that something had to be wrong with the studies finding the higher risks. Many general practitioners, gynaecologists, and family planners were swayed into accepting methodological arguments that sounded logical because of their legitimate concern with good contraception. However, few are really trained in the intricacies of epidemiological arguments. The companies exerted strong legal pressure on governments. Irresponsible scientists were accused of having caused a pill scare by juxtaposing selected figures without showing longer time trends in unwanted pregnancies. Irrelevant comparisons abounded, as with the risk of thrombosis in pregnancy.
The industry's view on bias and confounding was disproved by the World Health Organisation's scientific committee of leading epidemiologists who were not involved in the controversy.5 Given the pervasiveness of the competing interest caused by industry funding, BMJ readers should know whose words they read.
Source: PubMed Central
Language: English
Subfield: Issues, ethics and legal aspects
Field: Nursing
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1551137532