17 Feb 2010 --- A new study confirms that rates of obesity and other chronic health problems have risen in American children in recent years, but it also shows that many children's conditions will improve or resolve over time. The findings that appear in the Feb. 17 Journal of the American Medical Association support the need for continuous access to health services and suggest directions for future research.

"Although about half of all children will be obese or have another chronic health condition at some point during their childhood, less than half of them will have the same conditions six years later," says Jeanne Van Cleave, MD, of the Center for Child and Adolescent Health Policy at MassGeneral Hospital for Children, the study's lead author. "It looks like these chronic conditions may not be so permanent as we once thought."

Chronic health conditions are those – such as asthma, diabetes or attention-deficit hyperactivity disorder that require long-term treatment or interfere with a child's ability to perform the typical activities of children of the same age. Previous studies of the extent of these conditions in children have always looked at rates at a specific time. The current study was designed to analyze rates of chronic conditions over time and especially whether the incidence was increasing and if conditions persist or resolve over time.

The research team analyzed data collected in annual surveys conducted by the U.S. Bureau of Labor Statistics. Focusing on the children of women who became participants in a larger survey in 1986, the current study analyzed information from three groups of children who were ages 2 through 8 in 1988, in 1994 and in 2000. Every two years, in-home interviews – including height and weight measurement were conducted with both the children in these three groups and their mothers; and each group was followed for six years. Complete data were compiled for 2,337 children in the first group, 1,759 children in the second and 905 in the third group.

The results showed that the presence of chronic conditions when children entered the study increased from 11 percent in the 1988 group, to 16 percent in the 1994 group and 25 percent in the 2000 group. The likelihood of reporting a chronic condition during any part of the study period rose about 10 percent with each subsequent group from 30 percent in the first group to 50 percent in the third – but conditions persisted until the end of each study period only 40 percent of the time.

The authors note that some of the increase in chronic health conditions could be attributed to the fact that children in later groups were born to older mothers, which is known to increase the risk of health problems. While the study did not examine factors underlying the rise in obesity and other conditions, the investigators speculate that involved factors could range from food choices and lifestyle, to the greater survival of children with serious health problems, and the increased likelihood that health problems will be diagnosed.

"The prevalence of these chronic conditions speaks to the continuing need for high quality health care, especially primary care, where a lot of these conditions are diagnosed and treated," says Van Cleave, who is an instructor in Pediatrics at Harvard Medical School. "What we need to investigate now is why conditions resolve for some children and not for others – the rates of persistence didn't vary according to the type of health condition – and ways to prevent these conditions from developing in the first place."