I ran into the below today on reddit. My question is, are these trials as legitmate as they sound? Are there equally significant tests with different results that these need to be contrasted with? And finally, are the tests missing the mark--basically, are proponents of the treatment making a claim other than what is being tested here? I ask these questions because I want to avoid conclusion-shopping. I'm trying to think of every reason that the below could be misleading.
(bolding is the redditor's)Some guy on the Internet wrote: Hydroxychloroquine with or without Azithromycin in Mild-to-Moderate Covid-19
Among patients hospitalized with mild-to-moderate Covid-19, the use of hydroxychloroquine, alone or with azithromycin, did not improve clinical status at 15 days as compared with standard care.
A Randomized Trial of Hydroxychloroquine as Postexposure Prophylaxis for Covid-19
After high-risk or moderate-risk exposure to Covid-19, hydroxychloroquine did not prevent illness compatible with Covid-19 or confirmed infection when used as postexposure prophylaxis within 4 days after exposure.
Hydroxychloroquine in patients with mainly mild to moderate coronavirus disease 2019: open label, randomised controlled trial
Administration of hydroxychloroquine did not result in a significantly higher probability of negative conversion than standard of care alone in patients admitted to hospital with mainly persistent mild to moderate covid-19. Adverse events were higher in hydroxychloroquine recipients than in non-recipients.
A Cluster-Randomized Trial of Hydroxychloroquine as Prevention of Covid-19 Transmission and Disease
There was no significant difference in the primary outcome of PCR-confirmed, symptomatic Covid-19 disease (6.2% usual care vs. 5.7% HCQ; risk ratio 0.89 [95% confidence interval 0.54-1.46]), nor evidence of beneficial effects on prevention of SARS-CoV-2 transmission (17.8% usual care vs. 18.7% HCQ).
Hydroxychloroquine for Early Treatment of Adults with Mild Covid-19: A Randomized-Controlled Trial
No significant differences were found in the mean reduction of viral load at day 3 (-1.41 vs. -1.41 Log10 copies/mL in the control and intervention arm, respectively; difference 0.01 [95% CI -0.28;0.29]) or at day 7 (-3.37 vs. -3.44; d –0.07 [-0.44;0.29]). This treatment regimen did not reduce risk of hospitalization (7.1%, control vs. 5.9%, intervention; RR 0.75 [0.32;1.77]) nor shortened the time to complete resolution of symptoms (12 days, control vs. 10 days, intervention; p = 0.38). No relevant treatment-related AEs were reported.
Hydroxychloroquine in Nonhospitalized Adults With Early COVID-19: A Randomized Trial
Of 491 patients randomly assigned to a group, 423 contributed primary end point data. Of these, 341 (81%) had laboratory-confirmed infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or epidemiologically linked exposure to a person with laboratory-confirmed infection; 56% (236 of 423) were enrolled within 1 day of symptoms starting. Change in symptom severity over 14 days did not differ between the hydroxychloroquine and placebo groups (difference in symptom severity: relative, 12%; absolute, −0.27 points [95% CI, −0.61 to 0.07 points]; P = 0.117). At 14 days, 24% (49 of 201) of participants receiving hydroxychloroquine had ongoing symptoms compared with 30% (59 of 194) receiving placebo (P = 0.21). Medication adverse effects occurred in 43% (92 of 212) of participants receiving hydroxychloroquine versus 22% (46 of 211) receiving placebo (P < 0.001). With placebo, 10 hospitalizations occurred (2 non–COVID-19–related), including 1 hospitalized death. With hydroxychloroquine, 4 hospitalizations occurred plus 1 nonhospitalized death (P = 0.29).
Effect of Hydroxychloroquine in Hospitalized Patients with COVID-19: Preliminary results from a multi-centre, randomized, controlled trial.
Conclusions: In patients hospitalized with COVID-19, hydroxychloroquine was not associated with reductions in 28-day mortality but was associated with an increased length of hospital stay and increased risk of progressing to invasive mechanical ventilation or death.
RCTs almost perfectly control for variation between the tested groups. The only difference between the 2 groups in a good RCT is the treatment. Unlike observational studies that have unmeasured/unobserved confounding factors between the groups. It's why RCTs are the gold standard in research.