"Outcomes of hydroxychloroquine usage in United States veterans hospitalized with Covid-19"
- see https://www.medrxiv.org/content/10.1101/2020.04.16.20065920v1.full.pdf
From study:
“CONCLUSIONS: In this study, we found no evidence that use of hydroxychloroquine, either with or without azithromycin, reduced the risk of mechanical ventilation in patients hospitalized with Covid-19. An association of increased overall mortality was identified in patients treated with hydroxychloroquine alone. These findings highlight the importance of awaiting the results of ongoing prospective, randomized, controlled studies before widespread adoption of these drugs.”
The patients in this study were already hospitalized:
“We developed a cohort comprising patients with laboratory confirmed SARS-CoV-2 infection in an inpatient setting. SARS-CoV-2 status was classified by laboratory results that were extracted from VA laboratory data. A text search for SARS-CoV-2 laboratory tests was used to query VA lab results. The study index date was defined as the date of a hospitalization with a positive SARS-CoV-2 laboratory test. Index dates range from March 9, 2020 to April 11, 2020, and patients were followed from index until hospital discharge or death”
The key word in the veterans study (post 29) is “retrospective”. That means we have no idea if the patients were treated the same. It could be that when a patient was near death they tried the HC as a last resort, which would bias the results against HC.
Look instead for a double-blind, randomized study with a placebo or alternate drug.