Table 1.

Data adjusted to minimise clustering effect

Data values for total number and events to be divided by effect estimate across all studies Effect estimate: 1 + (M − 1)ICC M = average cluster size ICC = 0.03 (borrowed from Milsom 2006)	Total number of participants (original)	Total number of participants (adjusted)	Events ‒ original children attending dental office)	Events ‒ adjusted (children attending dental office)
Cunningham 2009 1 + (15 − 1).03 = 1.42 Control arm Traditional arm Criteria‐based arm	819 1175 958	577 827 675	129 165 151	91 116 107
Milsom 2006 1 + (42 − 1).03 = 2.23 Control arm Traditional arm Criteria‐based arm	4226 4418 4087	1895 1981 1833	1624 1838 1695	728 824 760
Praveen 2014 1 + (8 − 1).03 = 1.21 Control arm Intervention arm	300 300	248 248	80 54	67 45