Developmental-Behavioral Screening and Surveillance - Developmental-Behavioral Screening

Developmental-Behavioral Screening

Screening tools are brief measures designed to sort those who probably have problems from those who do not. Screens are meant to be used on the asymptomatic and are not necessary when problems are obvious. Screens do not lead to a diagnosis but rather to a probability of a problem. The kind of problem that may exist is generally not defined by a screening test. The screens used in primary care are generally broad-band in nature, meaning that they tap a range of developmental domains, typically expressive and receptive language, fine and gross motor skills, self-help, social-emotional, and for older children pre-academic and academic skills. In contrast, narrow-band screens focus only on a single condition such mental health problems, and may parse via factor scores, the probability, for example of depression and anxiety, versus attention deficits, versus disorders of conduct. Typically, broad-band screens are used first and may be the only type of measure used to make referrals in primary care, referrals which are then followed up by in—depth or diagnostic testing and often with narrow-band screens used alongside them.

Screening measures require careful construction, research, and a high level of proof. High quality screens are ones that have been standardized (meaning administered in exactly the same way every time) on a large current (meaning in the last decade) nationally representative sample. Screens must be shown to be reliable (meaning that two different examiners get virtually the same results, and that measuring the same child over a short period of time, e.g., two weeks, returns nearly the same result). Screens must have proven validity, meaning that they are given alongside lengthier measures and found to have a strong relationship (usually via correlations). Validity studies should also view which problems are detected (e.g., movement disorders, language impairment, autism spectrum disorder, learning disabilities).

But the acid test of a quality screen, and what sets apart the psychometry of screens from any other type of test, is proof of accuracy. This means that test developers must show proof of sensitivity, i.e., the percentage of children with problems detected, and specificity, meaning the percentage of children without problems who are identified usually with passing or negative test results. The standards for sensitivity and specificity are 70% to 80% at any single administration. While this may seem low, development is a moving target and repeated screening is needed to identify all in need. This also means that even quality screens make errors but, one study of four different screens showed that over-referrals (meaning children who fail screens but who are not found to be eligible for services upon more in-depth testing) are children with psychosocial risk factors and below average performance. This is helpful information for marshalling non-special education services, such as Head Start, after-school tutoring, Boys and Girls Clubs, parent training, etc. for a description of quality measures and links to publishers. Screens are expensive to produce, translate, support, etc. and so all developmental screens are copyrighted products that much be purchased from publishers. However, most are inexpensive to deliver with time and material costs between $1.00 - $4.00 per visit.