The Department of Thai Traditional and Alternative Medicine defended its study on the use of Andrographis paniculata, also known as green chiretta, to treat Covid-19 patients -- saying the herb can help patients with mild symptoms recover, despite the study's authors deciding not to publish it due to a statistical error.
The department's chief, Amporn Benjaponpitak, said the error contained in the study titled "Efficacy and safety of 'Andrographis paniculata' extract in patients with mild COVID-19: A randomized controlled trial", which was uploaded in the online pre-print journal medRxiv, does not affect the study's conclusion.
"We are confident in the accuracy of our study that green chiretta can prevent lung infections caused by Covid-19 from worsening," Dr Amporn said.
"The study's withdrawal has nothing to do with the government's policy to use green chiretta to treat patients with mild symptoms."
In the study, which was conducted on 56 Covid-19 patients with mild symptoms, 28 participants were given green chiretta extract, while the other 28 were given a placebo.
While the participants who were given green chiretta extract showed no signs of their lung infection worsening, so did several participants who took the placebo. This, according to Dr Amporn, led to a statistical miscalculation which prompted the authors to halt its publication.
According to Dr Amporn, the error relates to the study's P-value, which measures the likelihood of the study's hypothesis being valid. The lower the P-value, the more statistically significant the results.
The authors' miscalculated the study's P-value to be 0.03, while the figure should have been 0.112, she said.
As such, the research team decided to withdraw the study, and it would later be re-submitted for publication once the errors are fixed.
She further added that the department has also collected information from 4,541 patients who received green chiretta extract since the end of May from seven general hospitals, five field hospitals, a prison in Phetchaburi, Nonthaburi's Nimitre Butra center and Busarakam Hospital. She said none were found to have lung infections.
Dr Amporn's clarification came as a response to a comment made by Dr San Jaiyodsin, who claimed on his Facebook that there was not enough scientific information to back up the claim that green chiretta can prevent lung infections.