Virtually all of the 31/32 studies of early treatment using hydroxychlorquine had positive primary outcomes. In a sign test, if in reality HCQ had no benefit, the odds this happening is billions to one against.
14 of the outcomes were statistically significant.
Here are some of those studies, borrowing from the useful descriptions of c19study.com:
Sulaiman et al. “This observational prospective cohort study took place in 238 ambulatory fever clinics in Saudi Arabia, which followed the Ministry of Health (MOH) COVID-19 treatment guideline. This guideline included multiple treatment options for COVID-19 based on the best available evidence at the time, among which was Hydroxychloroquine (HCQ)”. https://www.medrxiv.org/content/10.1101/2020.09.09.20184143v1
In 5,541 patients the risk of hospitalisation was 38.6% lower in the patients WHO received HCQ, and the risk of death was 63.7% lower, https://c19hcq.com/sulaiman.html
Mokhtari et al. “This study was a multicenter, population-based national retrospective-cohort investigation of 28,759 adults with mild COVID-19 seen at the network of Comprehensive Healthcare Centers (CHC) between March and September 2020 throughout Iran. The baseline characteristics and outcome variables were extracted from the national integrated health system database.
Early administration of HCQ reduced the odds of hospitalization by 38%, and early administration of HCQ reduced the odds of death by 73%”. https://www.sciencedirect.com/science/article/pii/S1567576921002721
Szente Fonseca et al. A retrospective study. In a large HMO in Brazil, our approach was to allow treating physicians to prescribe antiviral medications immediately at presentation, and prednisone starting on day-6 of symptoms to treat pulmonary inflammation. We implemented this COVID-19 protocol for outpatients and studied 717 consecutive SARS-CoV-2-positive patients age 40 years or older presenting at our emergency rooms.
Risk of hospitalization, 64.0% lower, RR 0.36, p < 0.001, treatment 25 of 175 (14.3%), control 89 of 542 (16.4%), adjusted per study, odds ratio converted to relative risk, HCQ vs. nothing.
Risk of hospitalization, 50.5% lower, RR 0.49, p = 0.006, treatment 25 of 175 (14.3%), control 89 of 542 (16.4%), adjusted per study, odds ratio converted to relative risk, HCQ vs. anything else.
https://www.sciencedirect.com/science/article/abs/pii/S1477893920304026
Ip et al (added to the list of statistically significant outcomes as the primary outcome, hospitalization, is statistically significant )
Retrospective 1,274 outpatients, 47% reduction in hospitalization with HCQ with propensity matching, HCQ OR 0.53 [0.29-0.95]. Sensitivity analyses revealed similar associations.
Adverse events were not increased (2% QTc prolongation events, 0% arrhythmias).
Ip et al., 8/25/2020, retrospective, database analysis, USA, North America, peer-reviewed, 25 authors, dosage not specified.
risk of death, 54.5% lower, RR 0.45, p = 0.43, treatment 2 of 97 (2.1%), control 44 of 970 (4.5%).
risk of ICU admission, 28.6% lower, RR 0.71, p = 0.79, treatment 3 of 97 (3.1%), control 42 of 970 (4.3%).
risk of hospitalization, 37.3% lower, RR 0.63, p = 0.04, treatment 21 of 97 (21.6%), control 305 of 970 (31.4%), adjusted per study, odds ratio converted to relative risk. https://c19hcq.com/ip.html
The primary outcome was the reduced risk of hospitalization. There was also a reduction in death of 54.5% was not statistically significant.
https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-021-05773-w