Fig 1.
Flow diagram of the study selection process.
Table 1.
Description of eligible studies reporting the association between DPP-4i and the mortality of COVID-19.
Table 2.
Risk of bias assessment of the included studies according to the Newcastle-Ottawa Scale (NOS).
Fig 2.
Forest plots of ORs for the association between the DPP-4i use and the mortality of COVID-19.
Fig 3.
Funnel plot of the association between the DPP-4i use and the mortality of COVID-19.
Fig 4.
Sensitivity analysis of the effect DPP-4i use on the mortality of COVID-19.