TY - JOUR
T1 - Cross-diagnostic validity of the SF-36 physical functioning scale in patients with stroke, multiple sclerosis and amyotrophic lateral sclerosis
T2 - A study using Rasch analysis
AU - Dallmeijer, Annet J.
AU - de Groot, Vincent
AU - Roorda, Leo D.
AU - Schepers, Vera P.M.
AU - Lindeman, Eline
AU - van den Berg, Leonard H.
AU - Beelen, Anita
AU - Dekker, Joost
AU - Lankhorst, G. J.
AU - IJzerman, M. J.
AU - Beckerman, H.
AU - Prevo, A. J.
AU - Stam, H. J.
AU - Odding, E.
AU - van Baalen, B.
PY - 2007/3/1
Y1 - 2007/3/1
N2 - Objective: The aim of this study was to investigate unidimensionality and differential item functioning of the SF-36 physical functioning scale (PF10) in patients with various neurological disorders. Patients: Patients post-stroke (n = 198), with multiple sclerosis (n = 151) and amyotrophic lateral sclerosis (n = 193) participated. Methods: Unidimensionality of the PF10 within the patient groups was investigated by performing a separate Rasch analysis for each group. Differential item functioning was investigated in a pooled Rasch analysis of the 3 groups. Results: Within each group, all items fitted the Rasch model, except the "bathing/dressing" item in the amyotrophic lateral sclerosis group. The pooled analysis showed inadequate fit to the Rasch model for one item ("walking several hundred metres"). Of the other 9 fitting items, 5 showed differential item functioning for stroke vs multiple sclerosis and amyotrophic lateral sclerosis, while no differential item functioning was found between multiple sclerosis and amyotrophic lateral sclerosis. Conclusion: All items of the PF10, except one for the amyotrophic lateral sclerosis group, form a unidimensional scale, supporting the use of a sum score as a measure of physical functioning within these diagnostic groups. When comparing the data of patients after stroke, with that of patients with multiple sclerosis and/or amyotrophic lateral sclerosis patients, adjustments for differential item functioning are required.
AB - Objective: The aim of this study was to investigate unidimensionality and differential item functioning of the SF-36 physical functioning scale (PF10) in patients with various neurological disorders. Patients: Patients post-stroke (n = 198), with multiple sclerosis (n = 151) and amyotrophic lateral sclerosis (n = 193) participated. Methods: Unidimensionality of the PF10 within the patient groups was investigated by performing a separate Rasch analysis for each group. Differential item functioning was investigated in a pooled Rasch analysis of the 3 groups. Results: Within each group, all items fitted the Rasch model, except the "bathing/dressing" item in the amyotrophic lateral sclerosis group. The pooled analysis showed inadequate fit to the Rasch model for one item ("walking several hundred metres"). Of the other 9 fitting items, 5 showed differential item functioning for stroke vs multiple sclerosis and amyotrophic lateral sclerosis, while no differential item functioning was found between multiple sclerosis and amyotrophic lateral sclerosis. Conclusion: All items of the PF10, except one for the amyotrophic lateral sclerosis group, form a unidimensional scale, supporting the use of a sum score as a measure of physical functioning within these diagnostic groups. When comparing the data of patients after stroke, with that of patients with multiple sclerosis and/or amyotrophic lateral sclerosis patients, adjustments for differential item functioning are required.
KW - Amyotrophic lateral sclerosis
KW - Cross-diagnostic validity
KW - Differential item functioning
KW - Multiple sclerosis
KW - Physical functioning
KW - Rasch model
KW - Stroke
UR - http://www.scopus.com/inward/record.url?scp=33947727732&partnerID=8YFLogxK
U2 - https://doi.org/10.2340/16501977-0024
DO - https://doi.org/10.2340/16501977-0024
M3 - Article
C2 - 17351700
SN - 1650-1977
VL - 39
SP - 163
EP - 169
JO - Journal of rehabilitation medicine
JF - Journal of rehabilitation medicine
IS - 2
ER -