The rate of chronic health conditions among children in the U.S. increased from 12.8 percent in 1994 to 26.6 percent in 2006, for conditions such as obesity, asthma and behavior/learning problems, according to a study in the February 17 issue of JAMA.1
Understanding prevalence and dynamics of chronic conditions on a national scale is important when designing health policy, making accurate clinical predictions, and targeting interventions to prevent chronic conditions, according to background information in the article. Patterns of how childhood chronic conditions have changed over time have not been widely examined.
Jeanne Van Cleave, M.D., of MassGeneral Hospital for Children, Boston, and colleagues estimated changes in prevalence, incidence, and rates of remission of broad categories of conditions using 3 consecutive cohorts (groups) of children and examined the prevalence of having a condition during any part of the 6-year study period. The researchers used data from the National Longitudinal Survey of Youth-Child Cohort (1988-2006), which consisted of 3 nationally representative cohorts of children. Children were ages 2 through 8 years at the beginning of each study period, and the groups were followed up for 6 years, from 1988 to 1994 (cohort 1, n = 2,337), 1994 to 2000 (cohort 2, n = 1,759), and 2000 to 2006 (n = 905).
Items on the survey included reports by a parent of a child having a health condition that limited activities or schooling or required medicine, special equipment, or specialized health services and that lasted at least 12 months. Obesity was defined as a body mass index at or above the 95th percentile for age. Chronic conditions were grouped into 4 categories: obesity, asthma, other physical conditions, and behavior/learning problems.
The researchers found that prevalence of any chronic condition, including obesity, increased with subsequent groups. The prevalence at the beginning of the study for group 2 (16.6 percent) and group 3 (25.2 percent) was higher compared with group 1 (11.2 percent). The end-study prevalence of any chronic health condition was 12.8 percent for group 1 in 1994, 25.1 percent for group 2 in 2000, and 26.6 percent for group 3 in 2006.
Having a chronic condition was dynamic over time. Combining all groups, 16.6 percent of children had any chronic condition at the beginning of the study, and 20.8 percent reported a chronic condition at the end of the study period. “However, only 7.4 percent of all children reported a chronic condition both at baseline and at the end of the study period; 13.4 percent of participants represented new cases. For 9.3 percent of children, a chronic condition was reported at baseline but remitted by the study’s end.”
Additionally, the prevalence of having a chronic condition during any part of the 6-year study period was highest for group 3 (51.5 percent), and there were higher rates among male, Hispanic, and black youth.
“Chronic conditions in childhood are common and dynamic, underscoring the benefits of continuous, comprehensive health services for all children to adjust treatment of chronic conditions, promote remission, and prevent onset of new conditions. Future research should examine etiological differences between persistent and remitted cases,” the authors conclude.
Neal Halfon, M.D., M.P.H., of the University of California at Los Angeles, and Paul W. Newacheck, Dr.P.H., of the University of California at San Francisco, comment in an accompanying editorial on the findings of increasing chronic conditions among children2.
“The obesity epidemic seemed to develop at a time when many indicators suggested that children's health was generally improving. The data presented by Van Cleave et al suggest that the prevalence of other chronic health conditions is also increasing among U.S. children and that obesity is not the only clinical time bomb ticking away in children. There is an urgent need to better understand why this is the case and what can be done about it. Addressing the increasing incidence and prevalence of chronic conditions in children will ultimately require major reforms in the child health system. The child health system needs to do a better job preventing childhood chronic illness. The possibilities for such changes are substantial, as are the implications of not acting.”