Table 2:

Risk-of-bias assessment for mortality and length-of-stay outcomes using modified risk-of-bias criteria for randomized controlled trials and nonrandomized studies

Influenza trials, mortality outcomeSequence generationAllocation concealmentBlinding (patients)Blinding (health care providers)Blinding (outcome assessors)Blinding (data collectors)Blinding (data analyst)Loss to follow-up
Beigel et al., 2017 (25)Definitely yesDefinitely yesDefinitely yesDefinitely noProbably noDefinitely yesProbably noDefinitely no
Beigel et al., 2019 (26)Definitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesProbably yes
Davey et al., 2019 (27)Definitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yes
Hung et al., 2013 (24)Definitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yes
Non-RCT (SARS-CoV), mortality outcomeSelection of groupsExposure assessmentOutcome following exposureBaseline comparabilityMeasurement of prognostic variablesOutcome assessmentCompleteness of follow-upConcomitant treatments
Soo et al., 2004 (23)Definitely noProbably yesDefinitely yesDefinitely noDefinitely noDefinitely noDefinitely noDefinitely no
Influenza trials, length of staySequence generationAllocation concealmentBlinding (patients)Blinding (health care providers)Blinding (outcome assessors)Blinding (data collectors)Blinding (data analyst)Loss to follow-up
Beigel et al., 2019 (26)Definitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesProbably yes
Hung et al., 2013 (24)Definitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yesDefinitely yes
Beigel et al., 2017 (25)Definitely yesDefinitely yesDefinitely yesDefinitely noProbably noDefinitely yesProbably noDefinitely no
  • Note: RCT = randomized controlled trial, SARS-CoV = severe acute respiratory syndrome coronavirus.