NEILS is the first nationally representative study of Part C recipients (Hebbeler et al., 2001; Scarborough et al., 2004). Its main goal is to describe the population receiving Part C early intervention. NEILS was designed to provide descriptive and exploratory information about children and families, the services they receive, and their outcomes. A priority addressed by NEILS was to examine the outcomes experienced by children and families in early intervention. By definition, all children in NEILS were eligible for Part C services. Information in NEILS was acquired through caregiver interviews and Part C service providers.
Part C of IDEA was enacted in 1986 to address the critical need:
- to enhance the development of infants and toddlers with disabilities and to minimize their potential for developmental delay;
- to reduce the educational costs to our society, including our Nation's schools, by minimizing the need for special education and related services when infants and toddlers with disabilities reach school age;
- to minimize the likelihood of institutionalization of individuals with disabilities and maximize the potential for their independently living in society; and
- to enhance the capacity of families to meet the special needs of their infants and toddlers with disabilities.
In 1997, the reauthorization of Part C included in IDEA, required states to facilitate the development of a statewide comprehensive system of early intervention services entitling all children from birth through two years of age, experiencing developmental delays, as defined by the individual states, to Part C Services. IDEA regulations allow states considerable flexibility in the area of defining eligibility for services with specific criteria to determine eligibility left to the discretion of the individual states. Variability in eligibility criteria, along with the application of the definition of eligibility at the local level, the discipline of the professionals determining eligibility, and other community-based differences such as the availability of services and local child find efforts, creates significant variation in the percentage of children served in individual states and in the disability characteristics of those children (Scarborough et al., 2004).
One optional category for eligibility for Part C services is based on the presence of developmental delay or physical or mental conditions associated with developmental delay. Developmental delay is broadly defined as a documented delay in cognitive, communicative, physical, social or emotional, or adaptive development. Individual states determine the criteria for delay, including the severity and how it is documented, and if documented delay in multiple domains affects the severity criterion (Shackelford, 2006).
The second optional category for eligibility for Part C services is based on children with a medical diagnosis of a physical or mental condition associated with a high probability of developmental delay are likewise eligible for Part C services regardless of their developmental status. A chromosomal abnormality such as Down syndrome is an example of an established risk condition associated with a high probability of delay. Though states follow IDEA guidelines regarding the specific conditions of established risk, some have added additional disorders that constitute established risk.
The third optional category for eligibility is based on the presence of biomedical or environmental conditions placing children at risk of having substantial delay if early intervention services are not provided. There are well-known biological and environmental factors that place infants and toddlers at risk for developmental delay. Some commonly cited factors include low birthweight, respiratory distress as a newborn, lack of oxygen, brain hemorrhage, infection, nutritional deprivation, and a history of abuse or neglect. Risk factors do not inevitably lead to developmental difficulties, but indicate children who are at higher risk of developmental delay than children without these problems (Shonkoff & Meisels, 1991).
Currently five states (CA, HI, MA, NM, & WV) serve children at risk for developmental delay though there is considerable variability in the nature and number of risk factors that establish eligibility. California provides services only to children with biomedical risk, whereas Hawaii considers individual risk factors, such as maltreatment alone as potential eligibility for Part C. The remaining three states require 2 to 4 risk factors and recognize maltreatment as one of those factors.
Participants in NEILS were children between birth and 31 months of age entering Part C for the first time in 1997 and 1998. NEILS followed children from entry to Part C services annually during the time that services were received when the child was approximately 36 months of age and again during the childs kindergarten school year. Ninety-three counties in 20 states participated. These 20 states varied with regard to size, region of the country, and the agency that assumed lead responsibility for administering early intervention services. States also varied in terms of whether they served children identified on the basis of being at risk (Javitz, Spiker, Hebbeler, & Wagner, 2002). If a family had more than one child entering Part C services, only one was selected for the study. Programs invited 4,653 families to participate, and 3,338 (71%) agreed (Javitz et al., 2002).