et al., Clinical Infectious Diseases, ciaa1009, doi:10.1093/cid/ciaa1009 (Peer Reviewed)
This paper has inconsistent data - some of the values reported in Table 2 and the abstract correspond to 12 control hospitalizations, while others correspond to 11 control hospitalizations.
There was a 25% reduction in hospitalization and 16% reduction in the median time to symptom resolution for HC
Q, without statistical significance due to small samples.
Treatment delay is unknown at this time. They report a delay of up to 120 hours after symptoms plus an additional unspecified delay where medication was provided to patients at the first home visit. We have asked for details of the treatment delay and will update when hearing back. They do not break down results by treatment delay.
The paper does not mention zinc. Zinc deficiency in Spain has been reported at 83% , this may significantly reduce effectiveness. HC
Q is a zinc ionophore which increases cellular uptake, facilitating significant intracellular concentrations of zinc, and zinc is known to inhibit SARS-CoV RNA-dependent RNA polymerase activity, and is widely thought to be important for effectiveness with SARS-CoV-2 .
Undetectable viral load was changed to 3 log10 copies/mL potentially masking effectiveness. For viral load authors use nasopharyngeal swabs, we note that viral activity in the lung may be especially important for COVID-19, and that research has shown HC
Q concentrations can be much higher in the lung compared to plasma . We also note that viral detection by PCR does not equate to viable virus . Accuracy of the tests is not provided.
Nasopharyngeal viral load analysis issues include test unreliability and temporo-spatial differences in viral shedding .
293 low-risk patients with no deaths. No serious adverse events. We have asked for more details on the treatment delay and viral load change and will update when hearing back.
Also see this open letter: 
hospitalization, ↓25.0%, p=0.64
recovery time, ↓16.7%, p=0.38