Assessments of overweight that use methods not based on body mass index may grossly underdiagnose that condition in children, according to findings from a retrospective study.
During well-child visits, only 29% of overweight children were diagnosed as overweight and 1% of children at risk for overweight were classified as such using clinical impression as well as weight-for-age and weight-for-height percentiles.
Howard Taras, M.D., a member of the American Academy of Pediatrics Task Force on Obesity, said body mass index for age is recommended for determining overweight and risk for overweight in children, but most practices probably do not use it.
In most practices, a nurse or a nurse's aide records the height and weight at well-child visits into the patient's chart and may then plot them on a graph. Calculating the BMI for age just adds another step beyond that, he said in an interview.
In a 2-week period, 93 (20%) of 473 patients aged 2–18 years were categorized as overweight, and another 82 (17%) patients were categorized as at risk for overweight, reported Miriam V. Louthan, M.D., and her colleagues at the University of Louisville (Ky.).
They defined “at risk to be overweight” as BMI for age between the 85th and 95th percentile and overweight as BMI for age at the 95th percentile or greater (Clin. Pediatr. [Phila.] 2005;44:57–61).
“Severely overweight children are unlikely to be missed by any method of detection of overweight,” the investigators wrote, but “children who are younger and mildly overweight and who have more potential to have their disease process successfully interrupted are the ones who were typically missed by the non-BMI-based methods of identification.”
Most of the children who were overweight were younger than 12 years (68 patients), yet the physicians diagnosed significantly fewer of them than children older than 12 years (22% vs. 48%).
“I think we have to make sure that doctors feel that this is worthwhile, that it's going to change their management or change the instructions they give,” because it may take more money and staffing to direct additional clinical time to obesity, said Dr. Taras, professor of community pediatrics at the University of California, San Diego.
Physicians will have a better chance of reversing obesity in childhood and adolescence if they can refer patients to resources in the community on nutrition and physical activity that insurance will pay for, he added.
The physicians in the study gave 85% of the children diagnosed as overweight some sort of treatment plan, most of which consisted of recommendations for increased exercise, improved nutrition, and changes in eating patterns.
BMI-for-age percentiles for ages 2–20 years can be found at www.cdc.gov/nchs/about/major/nhanes/growthcharts/clinical_charts.htm