Disappointing Results From Trial of hydroxychloroquine/azithromycin in Paris: a brief paper review

(photo courtesy of pixabay.com and David Mark)

Jerome Groopman reports in the New Yorker that a study published on Tuesday from Paris shows no clinical benefit or improved viral clearance from the use of the famous drug combination so talked about lately.  Here is a link to the pdf of this pre-print (not peer-reviewed) paper.

When the study was published on March 28, the author reported only half a million cases; as of an hour ago, the world has 998,000 people who have been confirmed to have fallen ill.

The new study prospectively (beforehand) looked at eleven consecutive (one after the next) patients, two advantages that the Marseilles study did not boast.  Eight of ten patients studied (the one who died was excluded) were still shedding virus in nasopharyngeal swabs at days five to six after treatment initiation (start).  No apparent clinical improvement was seen.

While this study reported negative results with a stronger design, it is unclear as to why they did not wait a few more days to see if there was “late” improvement in viral shedding.  As noted before, the first Chinese series reported in 191 patients gave an average duration of shedding at 20 days.  The Marseilles study reported clearance at 5-6 days in all six patients with the drug combination.

A good “rule of thumb” for statistical interpretation of things in which the underlying distribution (the spread of possible results) is unknown: seven out of seven consecutive tests need to be positive, with no negative results, in order to believe in something to a 95% “confidence level”.  With eleven consecutive tests, you can only have one negative result if you want to be mildly confident in the positive finding.  This is known as nonparametric statistics.  Based on this, I say the Marseilles study is not good enough.

At this moment, the TV (MSNBC) tells me that cases worldwide stand at 1,002,000.  Metaphors like “speeding train” come to mind.  There is a momentum to this pandemic that is truly astounding.  It doesn’t look as if any drug or combination is going to be useful in the near future.