Using the half normal distribution to quantify covariate balance in cluster-randomized pragmatic trials

Table 3 Properties of I based on the normal distribution results from the central limit theorem applied to the half-normal distribution for 1 to 10 site-level variables

# of site-level variables	Mean	SD	10th percentile	25th percentile
1^a	0.798	0.602	0.026	0.392
2	0.798	0.426	0.252	0.511
3	0.798	0.348	0.352	0.563
4	0.798	0.301	0.412	0.595
5	0.798	0.269	0.453	0.616
6	0.798	0.246	0.483	0.632
7	0.798	0.228	0.506	0.644
8	0.798	0.213	0.525	0.654
9	0.798	0.201	0.541	0.663
10	0.798	0.191	0.554	0.669

SD standard deviation
^aDistribution is clearly not normal with only 1 site variable, so theoretical percentile values may be misleading in this case

ISSN: 1745-6215