Leo D. Roorda

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BACKGROUND Cross cultural validity is of vital importance for international comparisons. OBJECTIVE To investigate the validity of international Dutch-English comparisons when using the Dutch translation of the Western Ontario and McMaster Universities osteoarthritis index (WOMAC). PATIENTS AND METHODS The dimensionality, reliability, construct validity,(More)
OBJECTIVE When comparing outcomes of the Functional Independence Measure (FIM ) between patient groups, item characteristics of the FIM should be consistent across groups. The purpose of this study was to compare item difficulty of the FIM in 3 patient groups with neurological disorders. SUBJECTS Patients with stroke (n=295), multiple sclerosis (n=150),(More)
OBJECTIVES Knee osteoarthritis (OA) is a leading cause of activity limitations. The knee OA population is likely to consist of subgroups. The aim of the present study was to identify homogeneous subgroups with distinct trajectories of activity limitations in patients with early symptomatic knee OA and to describe characteristics of these subgroups. (More)
OBJECTIVE There is no consensus on the best method to determine the minimal important change (MIC) of patient-reported outcomes. Recent publications recommend the use of multiple methods. Our aim was to assess whether different methods lead to consistent values for the MIC. STUDY DESIGN AND SETTING We used two commonly used anchor-based methods and three(More)
OBJECTIVE To describe the osteoarthritis study population of CHECK (Cohort Hip and Cohort Knee) in comparison with relevant selections of the study population of the Osteoarthritis Initiative (OAI) based on clinical status and radiographic parameters. METHODS In The Netherlands a prospective 10-year follow-up study was initiated by the Dutch Arthritis(More)
OBJECTIVE To provide a practical example showing how to relate measurement error to minimal important change (MIC) to estimate sample sizes required for detecting important changes in research, and to determine the usefulness of patient-reported outcomes (PROs) in daily clinical practice. STUDY DESIGN AND SETTING The standard error of measurement (SEM)(More)
OBJECTIVE To give an overview of the literature on knee proprioception in knee osteoarthritis (OA) patients. METHOD A literature search was performed and reviewed using the narrative approach. RESULTS (1) Three presumed functions of knee proprioception have been described in the literature: protection against excessive movements, stabilization during(More)
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(More)
OBJECTIVE To identify subgroups or phenotypes of knee osteoarthritis (OA) patients based on similarities of clinically relevant patient characteristics, and to compare clinical outcomes of these phenotypes. METHODS Data from 842 knee OA patients of the Osteoarthritis Initiative were used. A cluster analysis method was performed, in which clusters were(More)
OBJECTIVE To predict the 2-year course of activity limitations in patients with early knee and/or hip osteoarthritis (OA). METHODS The Cohort Hip & Cohort Knee (CHECK) study is a prospective followup study. The CHECK cohort, comprising participants (n = 1,002) with early OA-related knee and/or hip symptoms, was followed for 2 years. Participants completed(More)