Pediatric evaluation of disability inventory : the Dutch adaption

Abstract

In Chapter 1 the theoretical concept of childhood disablement is explained. In addition, a brief introduction is presented, regarding pediatric functional status measurement, and more specifically the subject of this thesis: the Pediatric Evaluation of Disability Inventory. The aims and outline of the thesis are formulated. In Chapter 2 the applicability of the PEDI in the Netherlands is studied involving a sample of 20 Dutch children without disabilities. Their functional status outcome is compared to American peers; the Rasch statistical model was used to analyze the Dutch data. Score profiles were found not to be compatible with the score profiles of American children. More specifically, the data suggested inter-cultural differences. Based on this study, it is argued that cross-cultural validation of the PEDI was necessary before using it in the Netherlands. The translation and adaptation procedure in developing a Dutch version of the PEDI was based on current scientific guidelines in cross-cultural research as outlined in Chapter 3. A content validity study of the Dutch PEDI was subsequently performed and is also presented in this chapter. In this study, 31 allied health professionals completed a validity questionnaire. They confirmed the functional content and feasibility of the Dutch PEDI for pediatric functional status measurement. Both the adaptation process and content validity study generated the addition of eight new questions into the Dutch PEDI. Four of them are linked to an essential daily childhood activity in the Netherlands: ‘bicycling’. In Chapter 4 the reliability of the Dutch PEDI is examined. Therefore, parents of 64 children without disabilities and parents of 31 children with disabilities were interviewed. Inter-interviewer reliability was studied afterscoring audio-taped interviews by a second researcher. For intra-respondent reliability the same parent was interviewed twice within two weeks; for inter-respondent reliability both parents of a child were interviewed independently within a few days. The proportion of matching scores varied from 118 good to excellent in inter-interviewer reliability and inter-respondent reliability, and from moderate to excellent in intra-respondent reliability. Intraclass correlation coefficients were all excellent. Cronbach’s alpha (internal consistency) was calculated on a sample of 63 healthy children aged two years, and varied from excellent in the self-care and social function domain, to moderate in the mobility domain. Although some adaptations have to be made, good psychometric properties of the Dutch PEDI have been established. In Chapter 5 the discriminative validity of the Dutch PEDI is examined in 62 children without disabilities and in 197 children with disabilities (Infantile Encephalopathy, N= 40; Juvenile Idiopathic Arthritis, N= 20; Neurometabolic conditions, N=36; Neuromuscular Disorders, N= 9; Skeletal Disorders, N= 28; Spina Bifida, N= 41; Traumatic Injury, N= 23). Discriminant analysis revealed an excellent degree of sensitivity and specificity of the Dutch PEDI in identifying childhood disablement (non-disabled vs. disabled). The results also suggest the identification of subsets within the clinical samples: functional status linked to CNS involvement and musculo-skeletal involvement indicating potentials of the Dutch PEDI to discriminate within specific clinical groups. In Chapter 6 the responsiveness of the Dutch PEDI was examined. In contrast to traditional approaches, the responsiveness was measured at individual level. Children with Traumatic Injury (TI), Neuromuscular Diseases (NMD), and Juvenile Idiopathic Arthritis (JIA) (N=85) were measured three times. A Global Rating Scale (GRS) was used as an external standard of change; analyses were done at an individual level. Internal and external responsiveness were tested using ‘order restricted statistical inference’. The internal responsiveness of the PEDI varied from moderate to excellent. The external responsiveness varied from moderate to good. The study results support the author’s opinion that the Dutch PEDI is able to measure meaningful individual changes in functional status over time