Early hydroxychloroquine but not chloroquine use reduces ICU admission in COVID-19 patients
Lammers et al.
, Early hydroxychloroquine but not chloroquine use reduces ICU admission in COVID-19 patients
, Int. J. Infectious Diseases, doi:10.1016/j.ijid.2020.09.1460
Observational study 1,064 hospitalized patients in the Netherlands, 53% reduced risk of transfer to the ICU for mechanical ventilation with HCQ treatment starting on the first day of admission.
Weighted propensity score adjusted hazard ratio for transfer to the ICU with HCQ treatment, HR = 0.47, p
= 0.008. For CQ, HR = 0.8, p
= 0.207. Mortality results in this study are only for mortality before transfer to the ICU. The combined ICU/death HR was 0.68, p
= 0.024 for HCQ, and 0.85, p
= 0.224 for CQ.
Observational, multicenter, cohort study of hospitalized COVID-19 patients. 189 HCQ patients, 377 CQ, 498 control.
risk of death/ICU, 32.0% lower, HR 0.68, p = 0.02, treatment 30 of 189 (15.9%), control 101 of 498 (20.3%), adjusted per study.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Lammers et al., 29 Sep 2020, prospective, Netherlands, peer-reviewed, 18 authors.
Abstract: International Journal of Infectious Diseases 101 (2020) 283–289
Contents lists available at ScienceDirect
International Journal of Infectious Diseases
journal homepage: www.elsevier.com/locate/ijid
Early hydroxychloroquine but not chloroquine use reduces ICU
admission in COVID-19 patients
A.J.J. Lammersa,* ,1 , R.M. Brohetb,1 , R.E.P. Theunissena , C. Kostera , R. Roodc,
D.W.M. Verhagend , K. Brinkmane , R.J. Hassingf , A. Dofferhoffg , R. el Moussaouih ,
G. Hermanidesi, J. Ellerbroekj, N. Bokhizzouk , H. Visserl, M. van den Bergem , H. Baxn ,
D.F. Postmao , P.H.P. Groenevelda
Isala, Zwolle, The Netherlands
Department of Epidemiology and Statistics, Isala Academy, Zwolle, The Netherlands
Diakonessen Hospital, Utrecht, The Netherlands
Medisch Centrum Jan van Goyen, Amsterdam, The Netherlands
OLVG, Amsterdam, The Netherlands
Rijnstate, Arnhem, The Netherlands
Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
Maasstad Hospital Rotterdam, The Netherlands
Rode Kruis Hospital, Beverwijk, The Netherlands
Reinier de Graaf Gasthuis, Delft, The Netherlands
BovenIJ Hospital, Amsterdam, The Netherlands
Beatrix Hospital Gorinchem, The Netherlands
Admiraal de Ruiter Hospital, Goes, The Netherlands
Erasmus MC Rotterdam, The Netherlands
University Medical Center Groningen, Groningen, The Netherlands
A R T I C L E I N F O
A B S T R A C T
Received 1 August 2020
Received in revised form 23 September 2020
Accepted 23 September 2020
Background: The global push for the use of hydroxychloroquine (HCQ) and chloroquine (CQ) against
COVID-19 has resulted in an ongoing discussion about the effectivity and toxicity of these drugs. Recent
studies report no effect of (H)CQ on 28-day mortality. We investigated the effect of HCQ and CQ in
hospitalized patients on the non-ICU COVID-ward.
Methods: A nationwide, observational cohort study was performed in The Netherlands. Hospitals were
given the opportunity to decide independently on the use of three different COVID-19 treatment
strategies: HCQ, CQ, or no treatment. We compared the outcomes between these groups. The primary
outcomes were 1) death on the COVID-19 ward, and 2) transfer to the intensive care unit (ICU).
Results: The analysis included 1064 patients from 14 hospitals: 566 patients received treatment with
either HCQ (n = 189) or CQ (n = 377), and 498 patients received no treatment. In a multivariate propensitymatched weighted competing regression analysis, there was no signiﬁcant effect of (H)CQ on mortality
on the COVID ward. However, HCQ was associated with a signiﬁcantly decreased risk of transfer to the ICU
(hazard ratio (HR) = 0.47, 95% CI = 0.27–0.82, p = 0.008) when compared with controls. This effect was not
found in the CQ group (HR = 0.80, 95% CI = 0.55–1.15, p = 0.207).
Conclusion: The results of this observational study demonstrate a lack of effect of (H)CQ on non-ICU
mortality. However, we show that the use of HCQ — but not CQ — is associated with a 53% reduction in risk
of transfer of COVID-19 patients from the regular ward to the ICU. Recent prospective studies have
reported on 28-day, all-cause mortality only; therefore, additional prospective data on the early effects of
HCQ in preventing transfer to the ICU are still needed.
© 2020 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.
This is an open access article under the CC BY-NC-ND license..
is less effective
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