Methods
We selected as eligible studies parallel RCTs evaluating either
hydroxychloroquine (HQ) or chloroquine to treat patients diagnosed with
COVID-19, used alone or in any combination, and compared with any other
treatment option (including placebo). We selected HQ and chloroquine
because these drugs have received widespread support as effective
treatments for patients diagnosed with COVID-19 infection. These claims
arose following demonstration of in vitro viral activity against
SARS-CoV-2, and with potential viral load reduction in a case series
report.17, 18 In the United States, the FDA issued an
emergency use authorization to allow the use of these drugs in
adolescents and adults hospitalized for COVID-19 not participating in
clinical trials.19 Moreover, social media and
leadership support, lead to widespread shortages of the medication.
Traditionally, these immune-suppressants have been used to treat
autoimmune diseases such as rheumatoid arthritis and inflammatory bowel
disease; however, they have also been approved for the treatment of
malaria since 1955.20 Familiarity and potential
benefit have created a push for expedited clinical trials. We included
trials recorded in the clinical trial register of any country and at any
recruitment status. Uncontrolled trials and observational studies were
excluded.
We downloaded the COVID-19 WHO-ICTRP database
(https://www.who.int/ictrp/search/en/) on April
8th, 2020 at 10:30 GMT-6. On the database, we filtered
studies according to the intervention (HQ or chloroquine) and the study
design (randomized versus non-randomized). All the retrieved registers
were considered included and reviewed for data extraction purposes.
Patients and investigators were not aware of this study at the time of
their submissions.