OBJECTIVE: There is not a single universally accepted activity of daily living (ADL) instrument available to compare disability assessments across different patient groups. We developed a generic item bank of ADL items using item response theory, the Academic Medical Center Linear Disability Scale (ALDS). When comparing outcomes of the ALDS between patients groups, item characteristics of the ALDS should be comparable across groups. The aim of the study was to assess the differential item functioning (DIF) in a group of patients with various disorders to investigate the comparability across these groups. STUDY DESIGN AND SETTING: Cross-sectional, multicenter study including 1,283 in- and outpatients with a variety of disorders and disability levels. The sample was divided in two groups: (1) mainly neurological patients (n=497; vascular medicine, Parkinson's disease and neuromuscular disorders) and (2) patients from internal medicine (n=786; pulmonary diseases, chronic pain, rheumatoid arthritis, and geriatric patients). RESULTS: Eighteen of 72 ALDS items showed statistically significant DIF (P<0.01). However, the DIF could effectively be modeled by the introduction of disease-specific parameters. CONCLUSION: In the subgroups studied, DIF could be modeled in such a way that the ensemble of the items comprised a scale applicable in both groups.
OBJECTIVE: There is not a single universally accepted activity of daily living (ADL) instrument available to compare disability assessments across different patient groups. We developed a generic item bank of ADL items using item response theory, the Academic Medical Center Linear Disability Scale (ALDS). When comparing outcomes of the ALDS between patients groups, item characteristics of the ALDS should be comparable across groups. The aim of the study was to assess the differential item functioning (DIF) in a group of patients with various disorders to investigate the comparability across these groups. STUDY DESIGN AND SETTING: Cross-sectional, multicenter study including 1,283 in- and outpatients with a variety of disorders and disability levels. The sample was divided in two groups: (1) mainly neurologicalpatients (n=497; vascular medicine, Parkinson's disease and neuromuscular disorders) and (2) patients from internal medicine (n=786; pulmonary diseases, chronic pain, rheumatoid arthritis, and geriatric patients). RESULTS: Eighteen of 72 ALDS items showed statistically significant DIF (P<0.01). However, the DIF could effectively be modeled by the introduction of disease-specific parameters. CONCLUSION: In the subgroups studied, DIF could be modeled in such a way that the ensemble of the items comprised a scale applicable in both groups.
Authors: Martijn B A van der Wal; Wim E Tuinebreijer; Åsa Lundgren-Nilsson; Esther Middelkoop; Paul P M van Zuijlen Journal: Qual Life Res Date: 2014-02-09 Impact factor: 4.147
Authors: Michael Schuler; Gunda Musekamp; Jürgen Bengel; Sandra Nolte; Richard H Osborne; Hermann Faller Journal: Health Qual Life Outcomes Date: 2014-04-23 Impact factor: 3.186
Authors: Harald Baumeister; Birgit Abberger; Anne Haschke; Maren Boecker; Juergen Bengel; Markus Wirtz Journal: Health Qual Life Outcomes Date: 2013-08-02 Impact factor: 3.186
Authors: Stéphanie M van den Berg; Marleen H M de Moor; Matt McGue; Erik Pettersson; Antonio Terracciano; Karin J H Verweij; Najaf Amin; Jaime Derringer; Tõnu Esko; Gerard van Grootheest; Narelle K Hansell; Jennifer Huffman; Bettina Konte; Jari Lahti; Michelle Luciano; Lindsay K Matteson; Alexander Viktorin; Jasper Wouda; Arpana Agrawal; Jüri Allik; Laura Bierut; Ulla Broms; Harry Campbell; George Davey Smith; Johan G Eriksson; Luigi Ferrucci; Barbera Franke; Jean-Paul Fox; Eco J C de Geus; Ina Giegling; Alan J Gow; Richard Grucza; Annette M Hartmann; Andrew C Heath; Kauko Heikkilä; William G Iacono; Joost Janzing; Markus Jokela; Lambertus Kiemeney; Terho Lehtimäki; Pamela A F Madden; Patrik K E Magnusson; Kate Northstone; Teresa Nutile; Klaasjan G Ouwens; Aarno Palotie; Alison Pattie; Anu-Katriina Pesonen; Ozren Polasek; Lea Pulkkinen; Laura Pulkki-Råback; Olli T Raitakari; Anu Realo; Richard J Rose; Daniela Ruggiero; Ilkka Seppälä; Wendy S Slutske; David C Smyth; Rossella Sorice; John M Starr; Angelina R Sutin; Toshiko Tanaka; Josine Verhagen; Sita Vermeulen; Eero Vuoksimaa; Elisabeth Widen; Gonneke Willemsen; Margaret J Wright; Lina Zgaga; Dan Rujescu; Andres Metspalu; James F Wilson; Marina Ciullo; Caroline Hayward; Igor Rudan; Ian J Deary; Katri Räikkönen; Alejandro Arias Vasquez; Paul T Costa; Liisa Keltikangas-Järvinen; Cornelia M van Duijn; Brenda W J H Penninx; Robert F Krueger; David M Evans; Jaakko Kaprio; Nancy L Pedersen; Nicholas G Martin; Dorret I Boomsma Journal: Behav Genet Date: 2014-05-15 Impact factor: 2.805