Re: Effectiveness of home based early intervention on children’s BMI at age 2: randomised controlled trial
Author’s response to A/Prof Daymont’s comments:
In addressing A/Prof Daymont’s comments, we would like to provide additional data reporting differences in mean BMI-, weight-and length-for-age z-scores at 24 months using WHO Anthro.(1) As shown in the additional table, the intervention resulted in a significant reduction in BMI-for-age z-score of 0.29 (P=0.005). There were no significant differences in length-for-age z-score or weight-for-age z-score between the groups. The table also shows that the mean z-scores for BMI, weight and length were above 0 for both groups, and both groups had similar standard deviations (SD). Therefore, the intervention group as a whole was not underweight. In fact, using the WHO classification of underweight (weight-for-age z-score <−2) we had only two cases of underweight in our study: 0.4% (1/234) for the control and 0.4% (1/249) for the intervention group. We think it unlikely that an intervention that focuses on promoting healthy infant/child feeding, active play and a reduction in TV time would lead to poor growth. In addition, the reason for not including child sex in the baseline characteristics of our paper (Table 1)(2) was that we randomised the mothers before they gave birth. Despite a somewhat higher proportion of boys in the intervention group (53%, 131/249) than the control group (46%, 108/234), this difference was not statistically significant (P=0.16).
1. WHO Anthro for personal computers, version 3.2.2, 2011: Software for assessing growth and development of the world's children. Geneva: WHO, 2010 (http://www.who.int/childgrowth/software/en/).
2. Wen LM, Baur LA, Simpson JM, Rissel C, Wardle K, Flood V. Effectiveness of home based early intervention on children’s BMI at age 2: randomised controlled trial. BMJ 2012;344:e3732
Li Ming Wen, Louise Baur, Judy Simpson, Chris Rissel, Karen Wardle, and Vicki Flood
Competing interests: No competing interests