and data sets (if needed), and capable administration of institutional and government policies on the ethical conduct of human research.
Data on the extent of children’s participation in research are limited for most conditions. Most data located by the committee involve children with cancer. Cancer and heart disease are the leading disease-related causes of death for children, but they account for a small percentage of all childhood deaths. About half of childhood deaths occur in infancy (primarily as a result of congenital anomalies, short gestation, or complications related to pregnancy), and almost a third are the result of intentional or unintentional injuries (NCHS, 2000). As discussed elsewhere in this report, clinical trials of emergency care with both adult and pediatric populations face particular difficulties related to informed consent.
The National Cancer Institute (NCI) reports that in 1998 and 1999 some 50 percent of child cancer patients (ages 0 to 14 years) participated in clinical trials undertaken by NCI cooperative groups compared to 20 percent of patients ages 15 to 19 years and less than 3 percent of patients age 20 years or over (NCI, 2002b; data from Sateren et al., 2002; see also, Shochat et al., 2001). An earlier study based on data obtained from 1991 to 1994 reported that 70 percent of child cancer patients (ages 0 to 19 years) were enrolled in trials (Tejeda et al., 1996). A recent study calculated that about 70 percent of child cancer patients under age 15 years were registered by pediatric oncology trial groups compared to only 24 percent of patients ages 15 to 19 years (Liu et al., 2003).
The committee found no comparable data on the percentages of children with other conditions enrolled in clinical trials. A simple search of the NIH clinical trials website (http://www.clinicaltrials.gov/) generated a list of 163 leukemia studies for children from birth to age 17 years, 14 studies for cystic fibrosis, 12 studies for prematurity, and 29 studies for diabetes (all types). The search also yielded 146 studies for the terms infant and infancy, 238 for the term neonatal, and 159 for the terms adolescent and adolescence. The list of trials includes studies that do not test therapies. Closer examination of the listed studies suggests that some do not actually involve children. The number of studies is not a direct indicator of the total enrollment in clinical trials because trials vary greatly in size.
Some studies suggest that recruitment of children from minority populations may be particularly difficult. For example, in a longitudinal study of the risk factors for the development of cardiovascular disease during childhood, the recruitment of sufficient numbers of minority children took 2