Table 2.

Results for the worked example, calculated four different configurations of pilot trial to estimate the ICC. Integrative approach uses result (6).

	Scenario 1	Scenario 2	Scenario 3	Scenario 4
Pilot cluster size (m)	20	20	40	10
Total clusters in pilot (K)	4	8	4	8
Total participants in pilot (N)	80	160	160	80
Swiger's method
Estimated ICC 95% CI	0, 0.201	0, 0.149	0, 0.163	0, 0.201
Integrative approach
Total clusters	58	54	54	58
Total participants	2320	2160	2160	2320
Upper 95% CI limit approach
Total clusters	150	116	126	150
Total participants	6000	4640	5040	6000
Searle's method
Estimated ICC 95% confidence interval	0, 0.581	0, 0.275	0, 0.514	0, 0.353
Integrative approach
Total clusters	100	70	92	78
Total participants	4000	2800	3680	3120
Upper 95% CI limit approach
Total clusters	400	200	356	250
Total participants	16000	8000	14240	10000
Fisher's transformation
Estimated ICC 95% confidence interval	0, 0.322	0, 0.200	0, 0.268	0, 0.263
Integrative approach
Total clusters	70	58	64	64
Total participants	2800	2320	2560	2560
Upper 95% CI limit approach
Total clusters	230	150	194	192
Total participants	9200	6000	7760	7680

ICC: intra-cluster correlation.