Şehim Kutlay

Publications (2)1.88 Total impact

• Article: Validation of the World Health Organization disability assessment schedule II (WHODAS-II) in patients with osteoarthritis

  Şehim Kutlay, Ayşe A. Küçükdeveci, Atilla H. Elhan, Derya Öztuna, Nihal Koç, Alan Tennant
  [show abstract] [hide abstract]
  ABSTRACT: The objective of this study is to test the reliability and validity of WHODAS-II (Turkish version) for the assessment of disability in patients with osteoarthritis. This study is designed as follows: the internal construct validity of WHODAS-II in patients with knee osteoarthritis was assessed by Rasch analysis, and external construct validity by association with the Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC) and the Nottingham Health Profile (NHP); reliability was tested by internal consistency, intra-class correlation coefficient (ICC) and test–retest ICC. Our study presents the results of 225 outpatients assessed with mean age 58.4 years (SD 11.1) of whom 80.9% were female. Cronbach’s α, ICC, and test–retest ICC values for the six subscales of WHODAS-II varied between 0.71 and 0.94, 0.71 and 0.94, and 0.87 and 0.97, respectively. Rasch analysis of WHODAS-II indicated that after adjustment for local dependency, satisfactory fit was achieved. Two separate ‘activities’ and ‘participation’ components could also be identified. External construct validity of the scale was confirmed with expected correlations with WOMAC and NHP. This study concludes that WHODAS-II provides a reliable and valid health status instrument for measuring disability and components of ‘activities’ and ‘participation’ in patients with osteoarthritis. Thus, it provides the opportunity to model the consequences of disease according to the International Classification of Functioning, Disability and Health framework. KeywordsOsteoarthritis–Disability–Assessment–Rasch–Reliability–Validity
  Rheumatology International 04/2012; 31(3):339-346. · 1.88 Impact Factor
• Article: An initial application of computerized adaptive testing (CAT) for measuring disability in patients with low back pain

  Atilla Elhan, Derya Öztuna, Şehim Kutlay, Ayşe Küçükdeveci, Alan Tennant
  [show abstract] [hide abstract]
  ABSTRACT: Abstract Background Recent approaches to outcome measurement involving Computerized Adaptive Testing (CAT) offer an approach for measuring disability in low back pain (LBP) in a way that can reduce the burden upon patient and professional. The aim of this study was to explore the potential of CAT in LBP for measuring disability as defined in the International Classification of Functioning, Disability and Health (ICF) which includes impairments, activity limitation, and participation restriction. Methods 266 patients with low back pain answered questions from a range of widely used questionnaires. An exploratory factor analysis (EFA) was used to identify disability dimensions which were then subjected to Rasch analysis. Reliability was tested by internal consistency and person separation index (PSI). Discriminant validity of disability levels were evaluated by Spearman correlation coefficient (r), intraclass correlation coefficient [ICC(2,1)] and the Bland-Altman approach. A CAT was developed for each dimension, and the results checked against simulated and real applications from a further 133 patients. Results Factor analytic techniques identified two dimensions named "body functions" and "activity-participation". After deletion of some items for failure to fit the Rasch model, the remaining items were mostly free of Differential Item Functioning (DIF) for age and gender. Reliability exceeded 0.90 for both dimensions. The disability levels generated using all items and those obtained from the real CAT application were highly correlated (i.e. > 0.97 for both dimensions). On average, 19 and 14 items were needed to estimate the precise disability levels using the initial CAT for the first and second dimension. However, a marginal increase in the standard error of the estimate across successive iterations substantially reduced the number of items required to make an estimate. Conclusion Using a combination approach of EFA and Rasch analysis this study has shown that it is possible to calibrate items onto a single metric in a way that can be used to provide the basis of a CAT application. Thus there is an opportunity to obtain a wide variety of information to evaluate the biopsychosocial model in its more complex forms, without necessarily increasing the burden of information collection for patients.
  BMC Musculoskeletal Disorders. 01/2008;