Outcomes of Persons With COVID-19 in Hospitals With and Without Standard Treatment With (Hydroxy)ch loroquine
Retrospective study of HC
Q use in 9 hospitals in the Netherlands, showing no significant difference in mortality with HC
Q or dexamethasone. Late stage (admitted to hospital with positive test or CT scan abnormalities). 4 of 7 hospitals started treatment only after further deterioration. Short cutoff (21 days) - other studies have shown treated patient cases resolved faster and more control patients remaining in hospital at this time.
Significant differences between hospitals - HC
Q hospitals had significantly older patients with significantly more comorbidities. Non-HC
Q hospitals were "tertiary academic centres" whereas HC
Q hospitals were "secondary care hospitals". Residual confounding likely. This study compares overcrowded regular hospitals with undercrowded academic hospitals.
A subset of patients were excluded due to transfer to other hospitals. This introduces bias because patients in critical condition are not transferred. For examples, patients benefiting from HC
Q treatment may have been transferred to the tertiary centres and excluded from analysis, increasing the percentage of critical cases in the secondary hospitals.
Most patients received C
Q instead of the safer HC
Q, receiving late treatment with C
Q. Patients were given an initial dose of 600mg C
Q then every 12 hours, for 5 days a dose of 300 mg, for a total of 3600mg C
Q. This dose is likely to be toxic, see for example .
Authors mention a subset of hospitals started treatment relatively earlier, which seems like the most important area to analyze, but no results are provided.