Treatment delay (days since onset) Efficacy Efficacy by treatment delay in COVID-19 HCQ studies 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 -25% 0% 25% 50% 75% 100% c19hcq.org October 2023 mixed-effects meta-regression, most serious sufficiently powered outcome