A cluster RCT and process evaluation of an implementation optimisation intervention to promote parental engagement enrolment and attendance in a childhood obesity prevention programme: results of the Optimising Family Engagement in HENRY (OFTEN) trial

Table 5 Primary outcomes: pre-randomisation proportions, outcome proportions and risk differences adjusted for stratification factors

	Pre-randomisation^a (%)	Unadjusted model estimates^b			Adjusted model estimates^bc
	Pre-randomisation^a (%)	Outcome (%)	RD (95% CI)	p-value	RD (95% CI)	p-value	ICC
Primary outcome 1: enrolment
HENRY alone (n = 10 local authorities)	50.0	18.0	−0.3 (−19.1, 18.6)	0.978	−1.2 (−19.5, 17.1)	0.886	0.136
HENRY + optimisation intervention (n = 10 local authorities)	60.0	17.8
Primary outcome 2: attendance
HENRY alone (n = 10 local authorities)	50.0	13.9	3.1 (−13.3, 19.6)	0.695	1.2 (−15.7, 18.1)	0.881	< 0.001
HENRY + optimisation intervention (n = 10 local authorities)	50.0	17.1

^aCalculation of outcomes used data provided for randomisation
^bCalculation of outcomes used data from the most recently delivered HENRY programme during follow-up at 18 months post-randomisation
^cVariables controlled for in the adjusted analyses were as follows: proportion of children’s centres recruiting at least 8 parents per programme at randomisation, proportion of children’s centres retaining at least 75% of parents for a minimum of 5/8 sessions per programme at randomisation, proportion of children’s centres running at least one HENRY programme in 2015, size of local authority and proportion of children’s centres in the least/most deprived quintile as ranked by the 2015 Index of Multiple Deprivation at the Lower Layer Super Output Area
Abbreviations: RD risk difference, CI confidence interval, ICC intra-cluster correlation coefficient

ISSN: 1745-6215