Table 4.

Sensitivity analysis

Control proportion	Intervention proportion	Within-period ICC	Cluster autocorre-lation	Average cluster size per period	Absolute increase in proportion
0.5	0.61	0.06	0.8	100	0.110
	0.6	0.06	0.8	250	0.100
	0.59	0.06	0.8	400	0.090
	0.59	0.06	0.95	100	0.090
	0.565	0.06	0.95	250	0.065
	0.56	0.06	0.95	400	0.060
0.4	0.51	0.06	0.8	100	0.110
	0.5	0.06	0.8	250	0.100
	0.49	0.06	0.8	400	0.090
	0.49	0.06	0.95	100	0.090
	0.465	0.06	0.95	250	0.065
	0.46	0.06	0.95	400	0.060
0.45	0.56	0.06	0.8	100	0.110
	0.55	0.06	0.8	250	0.100
	0.545	0.06	0.8	400	0.095
	0.54	0.06	0.95	100	0.090
	0.515	0.06	0.95	250	0.065
	0.51	0.06	0.95	400	0.060

Sensitivity analysis showing detectable difference with a sample size of six practices, expressed as an absolute increase in proportions, with 80% power using a two-sided test at the 5% level of significance