Clinical trials are the basis of doctors' understanding of whether a drug is safe and effective. But the trials that get published aren't the whole story: Those that aren't favourable to the pharma companies' bottom line can often get swept under the rug.
Former FDA medical officer Erick Turner found that drug applications included studies with both positive and negative conclusions about their drug. Among antidepressants, for example, the ratio was about 50/50. But published studies — the ones you or I, or your doctor, would find by doing a PubMed or Google Scholar search — were 94 per cent positive. Published studies are more likely to be positive if they are funded by drug companies. "When the news is good, drug companies are going to see to it that the world knows about it and get the data published," Turner told Salon.
That's all old news, but a new analysis on anti-anxiety medications shows the bias still exists, even though drug trial results are now required to be reported on clinicaltrials.gov. Only 13 per cent of registered trials made their results available within a year of the trial's conclusion.
The result of this bias: it's possible drugs' reputations for effectiveness are overblown. Turner tells Salon this can affect how doctors work:
Before he began working at the FDA in 1998, Turner treated patients as a private psychiatrist and "naively believed all the literature I was reading. My assumption was the drugs work and when they don't, there's something unusual about the patient." Once he started working at the drug agency, he got to see a lot of negative studies that the public never saw and realised his assumptions had been wrong.
As a patient, you probably can't know whether unpublished studies would explain problems you're having with a drug, so consider this just a PSA about what's going on behind the scenes. You can keep up on the efforts to disclose more studies at alltrials.net, and read the full article at Salon for more information.