Evaluating research in developmental disabilities: a conceptual framework for reviewing treatment outcomes

Abstract

The study of developmental disabilities, not being confined to one medical field, poses a challenge in evaluating outcomes research. It is a multidisciplinary area of study which encompasses health-care, rehabilitation, psychosocial, educational, and biotechnology specialties and involves biological, social, and behavioral effects of intervention. Consequently, there is a lack of consistency in what has been studied, how the outcomes have been measured, and where these results have been recorded. Naturally, these disparate outcomes data need to be consolidated in such a way that comparison of treatments can be made, within and across professional disciplines. In an attempt to facilitate this, the American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) is committed to providing critical and useful appraisal of the scientific literature to help clinicians keep abreast in their own as well as other relevant disciplines 1. The Academy has explored several classification systems to consolidate and interpret data, and has established a two-part conceptual framework (1) to aggregate treatment outcomes and construct evidence tables based on a model of disablement which classifies treatment outcomes by the dimension in which they have an effect; and (2) to determine the degree of confidence that can be placed in the scientific evidence available in support of an intervention. Classification systems and models of disablement Before selecting a classification system, the AACPDM examined and carefully considered the merits of the most prominent classification in disablement models in rehabilitation as well as a system currently used to classify effects of orthope-dic surgery. The rehabilitation models were found to be more applicable to the multidisciplinary nature of developmental medicine. In 1980, the World Health Organization (WHO) developed a model of disablement; this model has had the most universal influence on rehabilitation. The model is described in two companion publications: the International Classification of Disease (ICD-10) 2 which classifies diseases, disorders or injuries; and the International Classification of Impairment, Disability and Handicap (ICIDH) 3 which describes the consequences of health conditions. The WHO model describes a key concept which is the basis of its classification system, i.e. that the consequences of disease occur at different levels: disease at the level of molecules and cells; impairment at the level of organs; disability at the level of individuals; and handicap at the level of society. The WHO's use of the term handicap for one of these levels became the subject of vigorous international debate. Consequently, the US Institute of Medicine (IOM) 4 and the US National Center for Medical Rehabilitation Research (NCMRR) 5 chose not to use the language of the ICIDH. Instead, they adopted the classification language of a conceptually similar model which was proposed by Nagi in 1969 6. Table I shows that this concept of reference levels is central to all the rehabilita...

How do changes in body functions and structures, activity, and participation relate in children with cerebral palsy?

“…29 In that model, shifts in 'impairment' were assumed to be precursors to changes in 'disability' (activity) that then became forerunners to changes in 'handicap' (participation). One can also consider the possibility of reverse or multidirectional influences in which changes in activity or participation might influence body functions and structures or a different area of activity, 32 as illustrated by the ICF model. When the predictor list for GMFM change was expanded to a higher outcome level to include PEDI FS mobility and PODCI global change scores in the regression analysis, the regression models changed, although no additional variation was explained (illustrated in Scenario 2, Appendix I).…”

Intervention for infants with brain injury: Results of a randomized controlled study

“…Specific studies on the efficacy of intervention on the outcome of children with brain injury are few, mostly due to the difficulty in conducting such studies and in diagnosing brain injury (Butler et al, 1999). Only five such studies are found in the literature.…”

“…Fazzi et al, 1997;Norr et al, 2003;Parker, Zahr, Cole, & Brecht, 1992;Schuler, Nair, & Kettinger, 2003;Zigler & Muenchow, 1992). Therefore, a rich environment with intensive stimulation may well allow infants with brain injury to recover.Specific studies on the efficacy of intervention on the outcome of children with brain injury are few, mostly due to the difficulty in conducting such studies and in diagnosing brain injury (Butler et al, 1999). Only five such studies are found in the literature.…”

Qualitative analysis of therapeutic motor intervention programmes for children with cerebral palsy: an update

“…To determine the value of the evidence available about an intervention, we applied Sackett's method for grading research (Sackett 1989) with minor modifications supported by research of the American Academy for Cerebral Palsy and Developmental Medicine (Butler et al 1999, Butler andDarrah 2001). Table III provides an overview of Sackett's levels of evidence for grading research.…”

“…The review of Vermeer and Bakx (1990) was chosen as a reference base for practical and methodological reasons: we had access to the database and notes that were made during (Sackett 1989) modified by Butler et al (1999) and Butler and Darrah (2001); see also Table III. -, unspecified; +limited; ++, detailed. Pre, non-randomized trial without control participants.…”