Statistical methods for primary and secondary outcomes {20a}
PEx
Individual demographics, baseline clinical characteristics (at enrolment and at the commencement of each PERIT), outcomes, and loss to follow-up are periodically reported for all PEx cohort participants. The proportion of participants with the primary endpoint measured, and any loss to follow-up, is assessed and reported. Categorical variables are summarized at each level as a frequency and proportion. Cell frequencies below five members are reported as “< 5” to ensure individual confidentiality. Continuous variables are summarized as mean and standard deviation for symmetric distributions and median and interquartile range (IQR) for asymmetric distributions.Continuous, categorical, and time-to-event endpoints may be assessed using standard statistical analytical approaches (chi squared, Fisher’s exact, Student 