Given the current COVID19 pandemic, having an RCT that could evaluate efficacy of PPE (personal protective equipment) would be of value to determine safety needs of Health care workers.

However, previous sample calculations for RCT for infection control required randomization of hundred of hospitals to detect a noticeable difference, making feasibility of such studies difficult.

@eliowa made me aware of this, as seen in this Jama study

Briefly, using event rates of MRSA infections from previous trials, this simulation study showed that their is a large coefficient of variance between clusters. When using the estimated CV with additional parameters such as (1) daily incidence rate of infection, (2) cluster size, (3) followup period, etc the authors were able to calculate different sample size requirements.

For Example:

âFor MRSA acquisition, using the calculated CV of 0.58 and assuming a mean of 7 patients at risk for MRSA acquisition per day per cluster, 50 clusters in total (25 in the intervention group and 25 in the control group) are required to observe a 30% decrease in MRSA acquisition daily rate, assuming a 1-year study with a type I error rate of 0.05 and a type II error rate of 0.20. If the effectiveness of the intervention were 10%, 540 clusters would be needed.â

My question:

The event rate for MRSA noted in prior calculations are much lower (~7 pts/day) then the volume seen currently at hospitals wtih COVID19 patients (20+ pts/day). Given this difference in event rate, would their be a noticeable difference in the CV and sample size requirements for a Hospital Cluster-RCT?

Is this study type, or an alternate study design, feasible to test efficacy of PPE? Or would sample requirements still be too high for a reasonable study?

References: