Re: Effectiveness of home based early intervention on children’s BMI at age 2: randomised controlled trial
I was very interested to read about the community-based intervention for obesity prevention described in “Effectiveness of home based early intervention on children’s BMI at age 2: randomised controlled trial.” I am writing to raise two concerns about the reporting of the trial.
The first, and more important, concern is that no information was provided regarding the proportion of children who were underweight as defined by BMI-for-age and weight-for-age in the control and intervention groups. Any intervention that results in a decrease in mean BMI has the potential to increase the proportion of children who are underweight. This information is important for interpretation of this study and would facilitate planning of future studies. Given the number of participants in the trial it is unlikely that there will be a statistically significant increase in the proportion of children who are underweight, just as there was no statistically significant decrease in the proportion of children who were overweight. It would also be useful to know whether, and in what manner, the intervention was modified for children who were gaining weight poorly.
The second concern is the lack of information regarding the sex of the child participants combined with the use of BMI rather than BMI-for-age z-score. Expected BMI at age 2 years of age (using length rather than height as is done in this study) is 15.4 kg/m2 for girls and 15.7 kg/m2 for boys according to the WHO growth standards.(1) Although it is likely that the proportions of males and females were similar between the groups given the randomized nature of the trial, I believe it is important to report the actual proportions.
1. WHO Multicentre Growth Reference Study Group. WHO Child Growth Standards Length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age: Methods and development [Internet]. 2006. Available from: http://www.who.int/childgrowth/publications/technical_report_pub/en/inde...
Competing interests: No competing interests