Table 2 Summary of the results of previous meta-analyses on observational studies
| Â | Author, Year | Included studies design | Number of included studies | Main Findings |
|---|---|---|---|---|
1 | Lao et al., 2022 | Retrospective observational which reported covariate adjusted effect estimates | 70 | Statin was associated with reduced mortality, ICU admission, and mechanical ventilation |
2 | Vahedian-Azimi et al., 2021 | Observational studies | 23 | Statin use had no significant effect on ICU admission and all-cause mortality, however, it decreased need for intubation |
3 | Diaz-Arocutipa et al., 2021 | Cohort studies | 25 | Unadjusted risk ratio meta-analysis did not show a reduction in mortality, while adjusted odds and hazard ratio meta-analysis resulted in significant association of statins and mortality reduction |
4 | Kow et al., 2021 | Original observational studies and preprints | 35 | Use of statins was associated with a significantly lower risk of all-cause mortality and endpoint of severe illness |
5 | Yetmar et al., 2021 | Cohorts and case–control studies (observational) | 19 | Prior statin use was associated with a lower risk of mortality and severe COVID-19 |
6 | Kollias et al., 2021 | Prospective or retrospective design | 22 | Statin use was associated with lower risk of mortality from COVID-19 |
7 | Zein et al., 2022 | Propensity-matched cohorts | 8 | Decreased mortality was observed to be associated with statin use |
8 | Chow et al., 2021 | Cohort studies | 13 | Risk of mortality was similar between statin users and non-users. However, the patients started their statin use after COVID-19 diagnosis had lower mortality |
9 | Wu et al., 2021 | Observational studies | 28 | Use of statins was significantly associated with decreased mortality and invasive mechanical ventilator support |
10 | Vahedian-Azimi, 2021 | Observational studies | 24 | Significant reduction was observed in statin users in terms of ICU admission, and death. However, no difference was observed in tracheal intubation |
11 | Hariyanto et al., 2021 | Observational studies | 35 | Statin use did not improve the composite poor outcomes of COVID-19 |
12 | Permana et al., 2021 | Retrospective cohort | 13 | In-hospital statin use was associated with reduced risk of mortality, while pre-admission use of statins was not related to mortality |
13 | Pal et al., 2022 | Observational studies | 14 | Unadjusted data meta-analysis revealed no improved clinical outcomes, while adjusted risk estimated showed significant reduction in adverse outcomes of COVID-19 |
14 | Hariyanto et al., 2020 | Observational studies | 9 | Statin use did not affect in-hospital outcomes of COVID-19 |