Hydroxychloroquine Plus Standard Personal Protective Equipment Versus Standard Personal Protective Equipment Alone for the Prevention of Laboratory Confirmed Covid-19 Infections Among Healthcare Workers: A Multi-Centre Parallel Group Randomized Controlled Trial from India

Background: Healthcare workers (HCWs),particularly from lower-middle income countries (LMIC), are at high risk of acquiring COVID-19.  Limited data exist on the effectiveness of hydroxychloroquine as prophylaxis. Our trial evaluated the effectiveness of a 12-week regimen of hydroxychloroquine among HCWs on the risk of laboratory-confirmed COVID-19 in the 6 months after randomization  Methods: We conducted a multicentre parallel-group open-label randomized controlled trial in 9 centres across India. HCWs serving in an environment with exposure to COVID-19 were eligible and randomized in a 1:1 ratio to hydroxychloroquine plus standard practice or to standard practice alone (role-appropriate personal protective equipment). In the intervention arm, participants received 2 doses of 400mg hydroxychloroquine at randomization followed by a weekly  dose for 12 weeks. The primary outcome was the proportion of laboratory-confirmed COVID-19 in the 6 months after randomization using an intention-to-treat analysis. The trial was registered on Clinical Trials Registry of India(CTRI/2020/05/025067).  Findings: From 29th June 2020 to 4th February 2021, 886 participants were screened and 416 were randomized (203-standard practice and 213- hydroxychloroquine plus standard practice). In the 6 months after randomization (primary analysis population=413), 11 participants assigned to the hydroxychloroquine group and 12 participants assigned to the standard practice group met the primary end point[ 5.1% vs 5.9%; OR 0.85, [95% CI 0.35-2.06] p=0.71]. There was no heterogeneity of treatment effect on the primary outcome in any  of the pre-specified subgroups. There were no significant differences in any of the secondary outcomes. The adverse event rates were 9.9% and 6.9% in the hydroxychloroquine and standard practice arms respectively. There were no serious adverse events in either group.  Interpretation: Hydroxychloroquine along with standard practice was not superior to standard practice alone on the proportion of lab-confirmed COVID-19. However, conclusions are limited by the premature trial cessation. Trial Registration: Clinical Trials Registry of India (CTRI/2020/05/025067). Funding: Wesley Medical Research, Australia Declaration of Interest: OJ reports being a member of the WHO R&D Blueprint Safety Monitoring Team, ACT Acclerator-R&D Digital Health working group and COVID-19 Clinical Research Coalition data sharing working group. Remaining authors have nothing to declare. Ethical Approval: Written informed consent was obtained from all participants. The trial was approved by the Ethics Committee at all participating sites (coordinating centre EC approval number: The George Institute Ethics Committee:08-2020)