Results
At least 32 individual observational studies have evaluated the effectiveness of outpatient statin treatment on the outcomes of COVID-19 patients admitted to hospital (supplementary information). These studies have used a variety of methods to reach different conclusions about the effectiveness of treatment. Seventeen reports conclude that statins reduce the occurrence of severe disease (e.g., ICU admission) or mortality. S1-S17 Nine reports conclude that statins might not be effective, but at least they are not harmful.S18-S26 Six others conclude that statin treatment is actually associated with harm.S27-S32 Seven meta-analyses of these studies (based largely on outpatient information) provide varying estimates of statin effectiveness.S33-S39 In contrast, eight observational studies show that in-hospital statin treatment is uniformly effective in reducing COVID-19 mortality (Table 1).S40-S47
None of the individual studies based on outpatient-documented treatment has mentioned the possibility of statin withdrawal after hospital admission. Moreover, none of the seven meta-analyses and only one of eight studies of in-hospital statin treatment has cited any reference on the detrimental effects of statin withdrawal.