Study protocol for Healthy Conversations @ Playgroup: a multi-site cluster randomized controlled trial of an intervention to promote healthy lifestyle behaviours in young children attending community playgroups

Table 2 Minimal detectable differences for child health behaviors and BMI z-score

Study Outcome	Hypothesised Effect	Est. SD	20 Playgroups (n = 120)	30 Playgroups (n = 180)	40 Playgroups (n = 240)
Veg Intake	½ serve, 38 g/d	58 g/d	26 g/d	21 g/d	18 g/d
Discretionary Foods	1.5 serv/d	2 serv/d	1 serv/d	0.7 serv/d	0.6 serv/d
% Time in PA	2.0%	5%	2.2%	1.8%	1.6%
Screen Time	30 min/d	75 min/d	33 min/d	27 min/d	24 min/d
Sleep Duration	40 min/d	96 min/d	43 min/d	35 min/d	30 min/d
BMI z-score	0.30	0.90	0.34	0.28	0.24

ISSN: 1471-2458