Table 2.
Summary of study characteristics
Citation | Locationa | Study period | Dominant variant(s) | Relevant analysis population (N) | Risk level of study population | Prior immunity (%) | MOV treatment initiation window | Approach to confounder adjustment |
---|---|---|---|---|---|---|---|---|
Arbel (2022) [29]b, c | Israel [41] | 16 Jan–31 Mar 2022 | Omicron (BA.1) |
40–64 years of age MOV: 224 Control: 6075 ≥ 65 years of age MOV: 845 Control: 12,724 |
≥ 40 years of age High risk for progression to severe disease Not eligible for NMV/r due to DDI or impaired kidney function |
Documented prior infection and/or ≥ 2 vaccine doses MOV: 93 Control: 92 |
≤ 5 days after positive test | Cox proportional hazards model with time-varying covariates for treatment assignment to address immortal time bias |
Bajema (2022) [30, 38]d | US [15] | 1 Jan–31 July 2022 | Omicron |
MOV: 3504 Control: 3504 |
≥ 18 years of age High risk for progression to severe disease |
≥ 1 vaccine dose MOV: 85.6 Control: 84.8 |
< 10 days after positive test |
Target trial emulation framework Exact and propensity score-matched cohorts Controls assigned index date same number of days after positive test as the treatment initiation date of matched MOV-treated individual to address immortal time bias |
Evans (2023) [31]e | UK [22] | 16 Dec 2021–22 Apr 2022 | Omicron (BA.1, BA.2) |
MOV: 359 Control: 4973 |
At highest risk for hospitalization/death |
≥ 1 vaccine dose Treated: 98.2f Control: 95.6 |
≤ 7 days after positive test | Cox proportional hazards model with time-varying covariate for treatment assignment to address immortal time bias |
Najjar-Debbiny (2023) [32]e | Israel [41] | 1 Jan–28 Feb 2022 | Omicron |
MOV: 2661 Control: 2661 |
≥ 18 years of age ≥ 1 comorbidity or condition associated with high risk for severe disease |
≥ 2 vaccine doses with most recent dose 7–180 days before diagnosis MOV: 74.6 Control: 76.1 |
≤ 5 days after positive test |
Propensity score-matched cohorts Cox proportional hazards model |
Paraskevis (2023) [33]b, c | Greece [42] | 2 Feb–5 Mar 2022 | Omicron (BA.1, BA.2) |
MOV: 4240 Control: 4240 |
≥ 65 years of age Risk factors for progression to severe disease |
≥ 1 vaccine dose MOV: 87.4 Control: 79.7 |
≤ 3 days after symptom onset or positive test |
Matched cohorts (by age and week of SARS-CoV-2 infection diagnosis); not adjusted for comorbidities due to unavailability of data for control group |
Wai (2023) [34]e | Hong Kong [18] | 22 Feb–31 Mar 2022 | Omicron |
MOV: 5345 Control: 23,430 |
≥ 60 years of age or < 60 years of age with ≥ 1 chronic disease | NR | ≤ 7 days after attending participating outpatient clinic |
Inverse probability of treatment weighting-adjusted Cox proportional Model Immortal time bias was not accounted for |
Wong (2022) [35]e | Hong Kong [18] | 26 Feb–26 Jun 2022 | Omicron (BA.2.2) |
MOV: 4983 Control: 49,234 |
≥ 60 years of age or ≥ 18 years of age with risk factors for progression to severe disease |
Fully vaccinatedg MOV: 16.1 Control: 12.4 |
≤ 5 days after positive test |
Propensity score-matched cohorts with Cox proportional hazards model in retrospective cohorts Time-varying covariate for treatment assignment to address immortal time bias Conditional logistic regression for case–control sensitivity analysis |
Xie (2023) [36]b, e | US [15] | 5 Jan–20 Oct 2022 |
Omicron (BA.1, BA.2, BA.5) |
MOV: 7818 Control: 78,180 |
≥ 1 risk factor for progression to severe disease |
≥ 1 vaccine dose MOV: 85.8 Control: 82.6 |
≤ 5 days after positive test |
Target trial emulation framework Propensity score-matched cohorts Clone method with inverse probability of censoring weighting, which also addressed immortal time bias |
Yip (2023) [37]e | Hong Kong [18] | 16 Feb–31 Mar 2022 | Omicron |
MOV: 4798 Control: 4758 |
Elderly (not defined) or high-risk with incomplete vaccination |
Complete vaccination: population rateh MOV: 36.1 Control: 55.9 |
≤ 5 days after positive test | Cox proportional hazards model with propensity score adjustment |
DDI drug–drug interaction, MOV molnupiravir, NMV/r nirmatrelvir/ritonavir, NR not reported, UK United Kingdom, US United States
‘Control’ defined as individuals not receiving any approved treatment for COVID-19 and used as comparator group for molnupiravir-treated arm
aReferences are to the guidelines for the use of molnupiravir in each location
bIdentified via supplemental literature surveillance
cPre-print
dIdentified as a pre-print and subsequently published as a peer-reviewed article with updated study period and results; the peer-reviewed version was included in the SLR
ePeer-reviewed study
fA combined prior immunity percentage was reported for all individuals receiving any treatment (molnupiravir, nirmatrelvir/ritonavir, and sotrovimab arms)
gDefined as ≥ 2 doses of BNT162b2 vaccine or ≥ 3 doses of Vero Cell or CoronaVac vaccine. The time since last vaccine dose was also measured
hDefined as ≥ 2 doses of BNT162b2 vaccine or ≥ 3 doses of CoronaVac vaccine. Vaccination data were available at a population-level; background vaccination rate was defined for each participant as the corresponding population vaccination rate on index date for individuals of the same age and gender