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