Table 1.
Characteristics of included studies.
| Author, Year [Reference] from, Study Location |
Study Design and Setting | No. of COVID-19 Tested Positive Patients | Exposure | Primary Outcome(s) |
|---|---|---|---|---|
| Elmunzer BJ et al., 2021 [22]; North America |
Cohort | 1846 | PPI use within 1 month (after hospital admission) | Lack of association between PPI use and severity; No association between use of PPI and mortality |
| Almario CV et al., 2020 [16]; USA |
Cohort | 3386 | PPI use once daily, and PPI use twice daily | Lack of association between PPI use and severity; No association between use of PPI and mortality |
| Lee SW et al., 2020 [23]; Korea |
Cohort | 4785 | Current PPI use (within 90 days before the first positive SARS-CoV-2 RNA test and before hospitalization) |
Severity (higher dose-PPI use and posthospitalization PPI use was significantly associated with severe COVID-19 symptoms) |
| Israelsen SB et al., 2021 [15]; Denmark |
CaseControl | 4473 | Current PPI use (within 90 days before the first positive SARS-CoV-2 RNA test and before hospitalization) |
Severity (hospital admission but not severe outcomes); No association found between PPI use and mortality |
| Liu JJ et al., 2021 [24]; MississiPPI |
Cohort | 56 | PPI use once daily; PPI use twice daily | Mortality |
| Fan X et al., 2021 [19]; United Kingdom |
Cohort | 9469 | PPI use (unspecified) | No significant association found between PPI use and mortality |
| Lee SW et al., 2020 [25]; Korea |
Cohort | 4785 | Current PPI use and past PPI use | Composite endpoint 1 (requirement of oxygen therapy, intensive care unit admission, administration of invasive ventilation, or death); Composite endpoint 2 (severed clinical outcomes of COVID-19, intensive care unit admission, administration of invasive ventilation, or death) |
| Zhou J et al., 2021 [26]; China |
Cohort | 4445 | Current PPI use and past PPI use | Severity |
| Ramchandran et al., 2020 [18]; USA |
Cohort | 295 | PPI use (unspecified) | Severity (risk for developing acute respiratory distress syndrome); Mortality |
| McKeigue PM et al., 2020 [27]; Scotland |
Matched Case Control | 4251 | Average daily doses of proton pump inhibitors | Severity and mortality (dose-response relationship was strongest in those PPI users aged less than 75 years) |
| Blanc F et al., 2020 [28], France |
Retrospective CaseControl | 89 | Current PPI use and past PPI use | COVID-19 incidence (PPI use lowered the risk of COVID-19 infection) |
| Huh K et al., 2020 [29]; Korea |
Case Control | 7341 | Past PPI use | No significant association found between PPI use and COVID-19 infection |
| Xiang Y et al., 2021 [17], China |
Cohort | 397,000 | Current PPI use and past PPI use | Risk of COVID-19 Infection, severity, and mortality; Protective association between PPI use and COVID-19 |
| Vila-Corcoles A et al., 2021 [30], Spain |
Cohort | 34,936 | Current PPI use | No significant association found between PPI use and COVID-19 infection |