Hydroxychloroquine as a primary prophylactic agent against sars-cov-2 infection: a cohort study
Kamstrup et al.
, Hydroxychloroquine as a primary prophylactic agent against sars-cov-2 infection: a cohort study
, International Journal of Infectious Diseases, doi:10.1016/j.ijid.2021.05.076
Retrospective HCQ users in Denmark, not showing a significant difference, however authors do not adjust for the very different baseline risk for systemic autoimmune disease patients.
Authors appear unaware of research in the area, for example saying that "currently, no obvious connection exists between a known rheumatological disorder and the risk of contracting SARS-CoV-2". Many papers show that the risk of COVID-19 for systemic autoimmune disease patients is much higher overall, e.g., Ferri et al. show OR 4.42, p
Supplementary data is not currently available.
This study is excluded in the after exclusion results of meta
not fully adjusting for the different baseline risk of systemic autoimmune patients.
risk of hospitalization, 44.0% higher, OR 1.44, p = 0.25, treatment 5,488, control 54,846, RR approximated with OR.
risk of case, 10.0% lower, HR 0.90, p = 0.23, treatment 188 of 5,488 (3.4%), control 2,040 of 54,846 (3.7%), NNT 340, adjusted Cox proportional hazards regression.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Kamstrup et al., 1 Jun 2021, retrospective, population-based cohort, Denmark, peer-reviewed, 21 authors.
Abstract: International Journal of Infectious Diseases 108 (2021) 370–376
Contents lists available at ScienceDirect
International Journal of Infectious Diseases
journal homepage: www.elsevier.com/locate/ijid
Hydroxychloroquine as a primary prophylactic agent against
SARS-CoV-2 infection: A cohort study
Peter Kamstrupa,* , Pradeesh Sivapalana , Joseﬁn Eklöfa , Nils Hoyera ,
Charlotte Suppli Ulrikb , Lars Pedersenc, Therese S. Lapperrec , Zitta Barrella Harboed,i ,
Uffe Bodtgere, Rasmus Dahlin Bojesenf , Kjell E.J. Håkanssonb , Casper Tidemandsenb ,
Karin Armbrustera , Andrea Browatzkid , Howraman Meterana , Christian Niels Meyerg,
Kristoffer Grundtvig Skaaruph , Mats Christian Højbjerg Lassenh , Jens D. Lundgreni,j ,
Tor Biering-Sørensenh,i,k , Jens-Ulrik Jensena,i,j
Section of Respiratory Medicine, Department of Medicine, Copenhagen University Hospital Herlev and Gentofte Hospital, Hellerup, Denmark
Department of Respiratory Medicine, Copenhagen University Hospital-Hvidovre, Hvidovre, Denmark
Department of Respiratory Medicine, Copenhagen University Hospital-Bispebjerg, Copenhagen, Denmark
Department of Pulmonary and Infectious Diseases, Copenhagen University Hospital North Zealand, Hillerød, Denmark
Respiratory Research Unit, Department of Respiratory Medicine, Næstved, Slagelse and Ringsted Hospitals, Næstved, Denmark
Department of Surgery, Næstved, Slagelse and Ringsted Hospitals, Slagelse, Denmark
Department of Medicine, Zealand University Hospital, Roskilde, Denmark
Department of Cardiology, Copenhagen University Hospital Herlev and Gentofte Hospital, Hellerup, Denmark
Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
PERSIMUNE & CHIP: Department of Infectious Diseases, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
A R T I C L E I N F O
A B S T R A C T
Received 16 April 2021
Received in revised form 17 May 2021
Accepted 28 May 2021
Objective: Hydroxychloroquine has been proposed as a primary prophylactic agent against coronavirus
disease 2019 (COVID-19). This study aimed to investigate if patients treated with hydroxychloroquine for
a non-COVID-19 indication had a lower risk of veriﬁed infection with severe acute respiratory syndrome
coronavirus-2 (SARS-CoV-2) compared with matched controls.
Methods: A cohort comprising all persons in Denmark collecting hydroxychloroquine prescriptions in
2020 and 2019 (i.e., both during and before SARS-CoV-2 was conﬁrmed in Denmark), matched by age and
sex with controls, was studied. Data were collected using the Danish national registries, which contain
complete information on patient health data, prescriptions and microbiological test results. The main
outcome was microbiologically veriﬁed SARS-CoV-2 infection.
Results: In total, 5488 hydroxychloroquine users were matched with 54,486 non-users. At baseline, the
groups differed in terms of diagnoses of pulmonary disease, cardiovascular disease, renal disease,
gastrointestinal/metabolic disease and dementia, as well as treatment with antirheumatic drugs. The
ﬁnal model was adjusted for these potential confounders. Use of hydroxychloroquine for non-COVID-19
indications was not associated with any change in conﬁrmed SARS-CoV-2 (hazard ratio 0.90, 95%
conﬁdence interval 0.76–1.07). This result was robust in..
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