Skip to main content

Table 2 Effective sample size, assuming different magnitudes of intracluster correlation (ICC)^

From: Fever, hyperglycaemia and swallowing dysfunction management in acute stroke: A cluster randomised controlled trial of knowledge transfer

ICC Design Effect Number of patients per group Total number of patients required
0 1 280 560
0.01 1.4 400 800
0.015 1.85 520 1040
0.02 2.6 730 1460
0.03 4.4 1230 2460
  1. ^ 80% power at alpha = 0.05; nine ACU's per group; adjusted for loss to follow-up of 10%