During the early days of the 2009 H1N1 influenza A pandemic, the popular herbal formula maxingshigan–yinqiaosan was used widely by TCM practitioners to reduce symptoms. (It’s hard to pronounce and spell, so I’ll refer to it as M-Y.) A new study was done to test whether M-Y worked and to compare it to the prescription drug oseltamivir. It showed that M-Y did not work for the purpose it was being used for: it did not reduce symptoms, although it did reduce the duration of one sign, fever, allowing researchers to claim they had proved that it works as well as oseltamivir.
“Oseltamivir Compared With the Chinese Traditional Therapy: Maxingshigan–Yinqiaosan in the Treatment of H1N1 Influenza” by Wang et al. was published in the Annals of Internal Medicine earlier this month. The study was done in China, which is notorious for only publishing positive studies. Even if it were an impeccable study, we would have to wonder if other studies with unfavorable results had been “file-drawered.” It’s not impeccable; it’s seriously peccable.
It was randomized, prospective, and controlled; but not placebo controlled, because they couldn’t figure out how to prepare an adequate placebo control. They considered that including a no treatment group compensated for not using a placebo control, and that objective temperature measurement could be expected to get around any bias. It might not: the nurses who took the temperatures were blinded to the study, but the patients were not. It’s possible that those who knew they were getting M-Y might have believed in it and their bias might have somehow subtly influenced data gathering so that M-Y appeared more equivalent to oseltamivir than it actually was.
There are other problems besides the lack of blinding. (more…)