"Meta-analyses," or reviews of several studies' worth of data on a single drug, influence patient care and healthcare policy. Increasingly, the people carrying out these meta-analyses have financial ties to drug companies. So researchers at Stanford and the University of California, San Francisco set out "to determine whether financial ties to one drug company are associated with favourable results or conclusions in meta-analyses on antihypertensive drugs," which are taken to lower blood pressure. They found a connection between drug company ties and meta-analyses with favorable conclusions, but not favorable results. That means that -- regardless of what the data actually showed -- meta-analyses done by people with financial ties were more likely to interpret the data as favorable to the drug. The researchers conclude that "meta-analyses, as with other study types, are open to the influence of systematic bias." Their findings also suggest "a failure of peer review," since "editors and peer reviewers must have read manuscript versions of those meta-analyses containing discordant results and conclusions, yet they did not prevent publication of biased conclusions."