Modification of the Upper Limb Functional Index to a Three-point Response Improves Clinimetric Properties
published online 07 December 2009.
Abstract
Study Design
Observational two-stage.
Introduction
To achieve optimal clinimetric properties for outcome measures, both practical and psychometric, ongoing improvements are required.
Purpose of the Study
To evaluate if the Upper Limb Functional Index (ULFI) clinimetric properties are improved by modification to a three-point response option and to verify the factor structure.
Methods
Stage 1, calibration (n=139) used ULFI dichotomous responses, and stage 2, validation (n=117) used a three-point response option. The clinimetric properties were compared in physical therapy outpatients with the QuickDASH as the reference standard. Repeated measurements were made at two to four weekly intervals.
Results
The ULFI three-point response option improved reliability [intraclass correlation coefficient (2,1)=0.98], internal consistency (α=0.92), QuickDASH concurrent validity (r=0.86), and responsiveness. Minimal detectable change (90% confidence interval) was 7.9%, and factor structure was unidimensional. Missing responses were <0.5%, and practical characteristics were unchanged.
Conclusions
The enhanced reliability and reduced errors with unchanged practicality demonstrate the ULFI improvements through modification to a three-point response option.
Level of Evidence
2c.
Faculty of Science, Centre for Healthy Activities, Sport and Exercise, University of the Sunshine Coast, Queensland, Australia
Department of Physical Therapy, Virginia Commonwealth University, Virginia, USA
Section of Medical and Surgical Sciences, Department of Orthopaedic Surgery, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
Faculty of Science, Centre for Healthy Activities, Sport and Exercise, University of the Sunshine Coast, Queensland, Australia
Correspondence and reprint requests to Charles Philip Gabel, MSc, Faculty of Science, Centre for Healthy Activities, Sport and Exercise, University of the Sunshine Coast, PO Box 760, Coolum Beach, Queensland 4573, Australia.
Presented at the 7th Triennial Congress of the International Federation of Societies for Hand Therapy, Sydney, 11th–15th March 2007.
ABSTRACT