Lewin did disclose on the second page of its report that it is part of Ingenix, which is a wholly owned subsidiary of the UnitedHealth Group, but noted that Lewin has editorial control over all of its work products. The press seems to have missed the point about Lewin’s pedigree. None of the stories I saw mentioned the UnitedHealth Group connection, important context for its findings. A bit of digging would have turned up more.

Last fall, Bryant Furlow, a staff reporter for the Rio Grande Sun in Espanola, New Mexico, who moonlights as a freelancer for The Lancet Oncology and as a medical muckraker with his Web site, epi Medical News & Expose, investigated just how much of a firewall existed between Lewin and Ingenix. Furlow noted in his piece that Lewin’s October study comparing the health plans of John McCain and Barack Obama did not disclose Lewin’s connection to United. So Furlow called up Lewin to ask why.

He learned that at that time “no corporate policy has been written to protect Lewin from interference by its parent companies.” In other words, there was no formal firewall. He reported that one senior Lewin official admitted that “autonomy is too strong a word” to describe the firm’s arrangement, but she denied that there had been editorial interference. Furlow pressed Lisa Chimento, a Lewin senior vice president, about disclosing the United connection. “It didn’t occur to us that we might have to address this,” she said. “In hindsight, maybe we should have.”

This time around, Lewin didn’t make that mistake. Next time around, media outlets shouldn’t either.

Trudy Lieberman is a fellow at the Center for Advancing Health and a longtime contributing editor to the Columbia Journalism Review. She is the lead writer for The Second Opinion, CJR’s healthcare desk, which is part of our United States Project on the coverage of politics and policy. Follow her on Twitter @Trudy_Lieberman.