Probably no drug has ever attracted such intense controversy as hydroxychloroquine in the Covid-19 era. Yet the evidence for its efficacy in treating Covid-19 at the early stage is straightforward. Virtually 100% of early treatment studies have recorded benefit from the drug. Accordingly, the controversy over early HCQ treatment has not arisen because of any insufficiency in the evidence.
As the existence of this evidence is our first Stubborn Truth it’s worth a look to see what it consists of.
Below is a list of all the studies that examined the effect of Hydroxychloroquine on early covid-19.
Handily, the website c19study.com is a very useful repository for covid-19 treatment studies. Study abstracts, sources are hyperlinked from the lead author’s name. There are brief description of main outcomes and any issues pertaining to the study.
It will probably redirect to https://c19hcq.com/, possibly reflecting the site’s beginnings in the HCQ controversy.
You can change the treatment, or timing of the treatment (early, late, PEP or PrEP), choose RCTs If you lose your way https://hcqmeta.com/
Alternatively the evidence can be reviewed at the very well-credentialed ECCE (Early Covid Care Experts) https://earlycovidcare.org/review-the-evidence.
The meaning of the numbers. Take the Esper study, for example.
Esper 64% 0.36 [0.15-0.87] hosp. 8/412 12/224 2.0
The number 0.36 is a risk ratio, signifying the risk using the treatment compared with the risk if not using the treatment (which is set to 1). As the outcome was in terms of risk of hospitalisation, it signifies the risk of hospitalization with the treatment was reduced by 64%. The interval [0.15-0.87] indicates the probable (statistical) error margins around the 0.36 figure. The upper range of the interval [0.15-0.87] being less than 1 indicates the result was classed as statistically significant, or unlikely to have arisen by chance. Another way of thinking about it is that if the interval doesn’t include 1 it means the treatment has changed the risk.
(On the other hand, if an intervention increased the risk, it would show in a risk ratio that was higher than 1, and statistical significance would be signified by an interval where the lower range was less than 1, eg [1.15-1.85].
For a quick intro to these mathematical interwoven concepts, you could try gatecrashing here)
The studies featured different clinical outcomes; deaths, recovery times, hospitalisation, viral clearance etc. With just one exception, they all recorded positive outcomes in terms of the benefit of HCQ use that was under investigation. Not all were statistically significant, though at least 13 were (more on this to come). As pointed out by C19study, the chance of 32 studies producing so many positive outcomes is billions to one against.
Finally the ‘Overall’ figure at the bottom combines the outcomes to arrive at a figure of 64% improvement, a notional, kind of average improvement.
Statistically, a risk ratio of 0.36 is highly significant as is shown by the confidence interval [0.29-0.46]; as the upper statistical limit 0.46 is well below one.
There is much more to be said about these studies…
Early treatment Hydroxychloroquine studies
Lead author Improvement RR [CI] Outcome Treatment Control Dose (4d)
Gautret 66% 0.34 [0.17-0.68] viral+ 6/20 14/16 2.4g
Huang (RCT) 92% 0.08 [0.01-1.32] no. recovr 0/10 6/12 4.0g(c)
Esper 64% 0.36 [0.15-0.87] hosp. 8/412 12/224 2.0
Ashraf 68% 0.32 [0.10-1.10] death 10/77 2/5 1.6g
Huang (ES) 59% 0.41 [0.26-0.66] viral time 32/32 37/37 2.0g (c)
Guérin 61% 0.39 [0.02-9.06] death 0/20 1/34 2.4g
Chen (RCT) 72% 0.28 [0.10-0.82] viral time 18/18 12/12 1.6g
Derwand 79% 0.21 [0.03-1.47] death 1/141 13/377 1.6g
Mitjà (RCT) 16% 0.84 [0.35-2.03] hosp. 8/136 11/157 2.0g
Skipper (RCT) 37% 0.63 [0.21-1.91] hosp./death 5/231 8/234 3.2g
Hong 65% 0.35 [0.13-0.72] viral+ 42/42 48/48 n/a
Bernabeu-Wittel 59% 0.41 [0.36-0.95] death 189 (n) 83 (n) 2.0g
Yu (ES) 85% 0.15 [0.02-1.05] death 1/73 238/2,604 1.6g
Ly 56% 0.44 [0.26-0.75] death 18/116 29/110 2.4g
Ip 55% 0.45 [0.11-1.85] death 2/97 44/970 n/a
Heras 96% 0.04 [0.02-0.09] death 8/70 16/30 n/a
Kirenga 26% 0.74 [0.37-1.48] recov. time 29/29 27/27 n/a
Sulaiman 64% 0.36 [0.17-0.80] death 7/1,817 54/3,724 2.0g
Guisado-Vasco (ES) 67% 0.33 [0.05-1.55] death 2/65 139/542 n/a
Szente Fonseca 64% 0.36 [0.20-0.67] hosp. 25/175 89/542 2.0g
Cadegiani 81% 0.19 [0.01-3.88] death 0/159 2/137 1.6g
Simova 94% 0.06 [0.00-1.13] hosp. 0/33 2/5 2.4g
Omrani (RCT) 12% 0.88 [0.26-2.94] hosp. 7/304 4/152 2.4g
Agusti 68% 0.32 [0.06-1.67] progression 2/87 4/55 2.0g
Su 85% 0.15 [0.04-0.57] progression 261 (n) 355 (n) 1.6g
Amaravadi (RCT) 60% 0.40 [0.13-1.28] no recov. 3/15 6/12 3.2g
Roy 2% 0.98 [0.45-2.20] recov. time 14 (n) 15 (n) n/a
Mokhtari 70% 0.30 [0.20-0.45] death 27/7,295 287/21,464 2.0g
Million et al. 83% 0.17 [0.06-0.48] death 5/8,315 11/2,114 2.4g
Sobngwi (RCT) 52% 0.48 [0.09-2.58] no recov. 2/95 4/92 1.6g
Rodrigues (RCT) -200% 3.00 [0.13-71.6] hosp. 1/42 0/42 3.2g
Sawanpanyalert 42% 0.58 [0.18-1.91] progression n/s n/a varies
Overall
Early treatment 64% 0.36 [0.29-0.46] 148/20,390 996/34,231
(hcqmeta.com Sep 24, 2021)