A call for study participants

April 30, 2007

The National Health and Nutrition Examination Survey (NHANES) is looking for 8- to 19-year olds to conduct validation research of a new data collection method. An alternative method for obtaining information on sexual maturation is under development at the CDC's National Center for Health Statistics. The method uses audio computer-assisted self-interview (ACASI) technology. The module was developed in .net 2.0 and runs on Microsoft Windows as a stand-alone version or in an integrated mode with a server.

The National Health and Nutrition Examination Survey (NHANES) is looking for 8- to 19-year olds to conduct validation research of a new data collection method. An alternative method for obtaining information on sexual maturation is under development at the CDC's National Center for Health Statistics. The method uses audio computer-assisted self-interview (ACASI) technology. The module was developed in .net 2.0 and runs on Microsoft Windows as a stand-alone version or in an integrated mode with a server.

Sexual maturation correlates with numerous physical, biochemical, and psychosocial changes that occur during childhood and adolescence. During NHANES III, 1988-94, physicians performed a visual Tanner stage examination to assess the sexual maturation status of children and adolescents 8-18 years of age. This information was used to interpret the NHANES anthropometry, body composition, and laboratory findings. Sexual maturation has not been assessed in NHANES since 1994 because of concerns about privacy and the sensitivity of the physical examination. However, the loss of this information is a limitation for interpreting NHANES data, particularly the anthropometry, body composition, and laboratory results.

Medical illustrations were developed by a medical illustrator at the National Institutes of Health. A categorical classification scale based on the Tanner stages of maturation was used for sets of female breast, male and female pubic hair, and male genitalia drawings. The drawings are numbered from 1 to 5; drawing 1 is the pre-pubertal (Tanner stage 1) and stage 5 is the fully mature/adult stage (Tanner stage 5). The module was designed such that children 8-9 years of age will view the first 4 stages of development for each body site; children and teens 10-19 years will view five stages of development for each body site. Participants will view printed text descriptions and listen to an audio script describing each drawing. Respondents are asked to select the drawing that looks the most like their body. Response selections can be made using a computer mouse or by touching the computer screen. Respondents may choose not to answer the questions or to end the interview.

NHANES is conducted to assess the health and nutritional status of the civilian, non-institutionalized US population. Standardized household interview and health examination methods have been used to collect survey data on a periodic basis between 1971 and 1994, and continuously since 1999. The current survey sample design includes samples of adolescents 12-19 years, Mexican Americans, and African Americans. The NHANES health examination includes body measurement and dual energy x-ray absorptiometry (DXA) examinations, dietary interviews, health interviews, clinical tests, and extensive laboratory studies.

Validation research is planned with children and adolescents 8-19 years of age, to compare the accuracy of the ACASI self-assessment results to examination results determined by trained health examiners. If the validation results are favorable, further testing will be done to determine if the method can be used in NHANES. For more information on the module, please contact Margaret McDowell, MPH, RD at CDC/NCHS, 3311 Toledo Road, Room 4335, Hyattsville, Md. 20782. Email: MMcDowell@cdc.gov.