Prevalence and assessment of attention-deficit/hyperactivity disorder in primary care settings.

Research literature relating to the prevalence of attention-deficit/hyperactivity disorder (ADHD) and co-occurring conditions in children from primary care settings and the general population is reviewed as the basis of the American Academy of Pediatrics clinical practice guideline for the assessment and diagnosis of ADHD. Epidemiologic studies revealed prevalence rates generally ranging from 4% to 12% in the general population of 6 to 12 year olds. Similar or slightly lower rates of ADHD were revealed in pediatric primary care settings. Other behavioral, emotional, and learning problems significantly co-occurred with ADHD. Also reviewed were rating scales and medical tests that could be employed in evaluating ADHD. The utility of using both parent- and teacher-completed rating scales that specifically assess symptoms of ADHD in the diagnostic process was supported. Recommendations were made regarding the assessment of children with suspected ADHD in the pediatric primary care setting.

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. I. Birth defects and developmental disorders.

Members of the workgroup on birth defects and developmental disorders discussed methods to assess structural anomalies, genetic changes and mutations, fetal and infant mortality, functional deficits, and impaired fetal and neonatal growth. Tier 1 assessments for all five adverse reproductive outcomes consist of questionnaires and reviews of medical records rather than laboratory testing of biologic specimens. The work-group members noted a role for neurodevelopmental testing and for limited genetic studies, such as karyotyping in Tier 2 assessments. Emerging methodologies to identify chromosomal aberrations, DNA adducts, and repair inhibition were reserved for Tier 3.

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. II. Female reproductive disorders.

Members of the workgroup on female reproductive disorders discussed methods to evaluate five principal functions: menstrual dysfunction, infertility, pregnancy loss, lactation disorders, and pregnancy complications. To test each function, a nested strategy was considered, based on progressive levels of effort available to conduct field investigations. This strategy was analogous to the three-tier classification of biomarkers used by other workshops. The lowest level of effort, corresponding to Tier 1, consists only of questionnaires, diaries, and reviews of maternal and infant medical records. The medium level of effort (Tier 2) collects data from questionnaires and diaries, and some biologic specimens. Suggested laboratory analyses included measurement of progesterone in saliva and several glycoprotein hormones in urine that evaluate menstrual dysfunction, infertility, and pregnancy loss. The highest level of effort (Tier 3) involves prospective collection of diary information and simultaneous collection of biological specimens.

Selective approaches to basic neurobehavioral testing of children in environmental health studies.

To identify neurotoxic effects in children living near hazardous waste sites, the Agency for Toxic Substances and Disease Registry (ATSDR) has designed a basic Pediatric Environmental Neurobehavioral Test Battery (PENTB) for children 1 through 16 years of age. It emphasizes tests appropriate to the stages of a child's development. These stages were fundamental factors in selecting tests for the PENTB, which includes both informant- and performance-based assessment procedures. Assessment of children under 4 years of age is restricted to four informant-based instruments, to evaluate as many functions as possible while minimizing testing time and the professional expertise needed in the test setting. The assessment of children 4 through 16 years of age includes 10 performance-based tests to evaluate key functions within the cognitive, motor, and sensory domains analogous to functions affected by neurotoxic chemicals in adults. In all age groups, it is crucial to also assess family, cultural, economic, and other potentially confounding variables.

Assessment of mercury neurotoxicity through psychometric and neurobehavioral testing: session summary.

Neurobehavioral disorders are well-recognized among the adverse health effects of exposure to mercury. The effort to characterize these effects in animals and humans has progressed steadily over several decades. This has included a variety of study designs, and employed a variety of measurement techniques to evaluate exposure of individuals and populations. The Twelfth International Neurotoxicology Conference, Neurotoxicity of Mercury: Indicators and Effects of Low-Level Exposure, included a plenary session on the predictive value of psychometric and neurobehavioral testing of animals and humans in assessing neurotoxic effects. This session provided a broad view of the methods currently in use to measure adverse effects on the nervous system, in particular those effects that might be attributed to mercury exposure.

Health impact of measles vaccination in the United States.

As a result of intensive efforts to vaccinate children, measles and its attendant complications of encephalitis and death have declined more than 99% from the prevaccine era. Similarly, subacute sclerosing panencephalitis has declined markedly. Measles vaccine has been demonstrated to be extremely safe, as well as extremely effective. The health and resource benefits due to vaccination against measles during the first 20 years of vaccine licensure have been enormous. In this period it is estimated that vaccination against measles has prevented 52 million cases, 5,200 deaths, and 17,400 cases of mental retardation, achieving a net savings of $5.1 billion. These substantial health and resource benefits of measles vaccination will continue to accrue in the future.

Impact of measles in the United States.

Measles has had a severe impact on children in the United States since colonial times. In the early decades of the 20th century, thousands of fatal measles infections were reported each year. During the 1950s an annual average of greater than 500,000 cases of measles and nearly 500 deaths due to measles were reported in the United States. Surveys indicated that 95% of the population had been infected with measles by the age of 15 years. The introduction of measles vaccine and its widespread use, which began in 1963, has had a major impact on the occurrence of measles in the United States. Reported numbers of cases, deaths due to measles, and complications of measles (e.g., encephalitis) have declined dramatically. Accompanying the decline in reported incidence of measles and following it by approximately seven years, has been a decline in the reported incidence of subacute sclerosing panencephalitis (SSPE). In recent years, the incidence of measles has dropped to levels that are less than 1% of those seen in the prevaccine era. In 1981, provisional figures indicated that only 10% of counties in the United States reported any cases of measles. The reported incidence in 1981 was 1.3 cases per 100,000 population, compared with an average incidence of 336.3 cases per 100,000 population in the decade 1950-1959. Thus, the impact of measles in the United States has been markedly reduced, and it is anticipated that indigenous transmission will be eliminated entirely from the country within the year.