Statistical Analyses
At the prevalence study (asymptomatic cohort) design stage, it was
estimated that the asymptomatic prevalence of SARS-Co-V-2 would likely
range between 15 and 20% (17). The sensitivity of current RT-PCR assays
for SARS-CoV-2 has not been published but was expected to range from
70-90%. Specificity was expected to be above 90%. Therefore, to
adequately power a study with a 10% prevalence rate would require
between 355 and 574 patients, while if prevalence was found to be 20%
this study would require between 462 and 733 patients. Median and
interquartile range (IQR) are calculated for continuous variables, while
counts and percentages are used to describe categorical variables. The
Clopper-Pearson interval was used to find a 95% confidence interval for
the probability of having positive seroprevalence results.