@article{ProdingerO'ConnorStuckietal.2017, author = {Prodinger, Birgit and O'Connor, R.J. and Stucki, G. and Tennant, A.}, title = {Establishing score equivalence of the Functional Independence Measure (FIM™) motor scale and the Barthel Index, utilising the International Classification of Functioning, Disability and Health (ICF) and Rasch Measurement Theory}, series = {Journal of Rehabilitation Medicine}, volume = {49}, journal = {Journal of Rehabilitation Medicine}, number = {5}, pages = {416 -- 422}, year = {2017}, abstract = {Introduction: Two widely used outcome measures to assess functioning in neurological rehabilitation are the Functional Independence Measure (FIM™) and the Barthel Index. The current study aims to establish the equivalence of the total score of the FIM™ motor scale and the Barthel Index through the application of the International Classification of Functioning, Disability and Health, and Rasch measurement theory. Methods: Secondary analysis of a large sample of patients with stroke, spinal cord injury, and multiple sclerosis, undergoing rehabilitation was conducted. All patients were assessed at the same time on both the FIM™ and the Barthel Index. The International Classification of Functioning, Disability and Health Linking Rules were used to establish conceptual coherency between the 2 scales, and the Rasch measurement model to establish an exchange of the total scores. Results: Using the FIM™ motor scale, items from both scales linked to the International Classification of Functioning, Disability and Health d4 Mobility or d5 Self-care chapters. Their co-calibration satisfied the assumptions of the Rasch model for each of 3 diagnostic groups. A ceiling effect was observed for the Barthel Index when contrasted against the FIM™ motor scale. Conclusion: Having a Rasch interval metric to transform scores between the FIM™ motor scale and Barthel Index is valuable for monitoring functioning, meta-analysis, quality audits and hospital benchmarking.}, language = {en} } @article{ProdingerCoenenHammondetal.2020, author = {Prodinger, Birgit and Coenen, Michaela and Hammond, Alison and K{\"u}{\c{c}}{\"u}kdeveci, Ayse A. and Tennant, Alan}, title = {Scale-Banking for Patient Reported Outcome Measures (PROMs) Measuring Functioning in Rheumatoid Arthritis: A Daily Activities Metric}, series = {Arthritis Care \& Research}, journal = {Arthritis Care \& Research}, year = {2020}, abstract = {Objective: Functioning is an important outcome for rheumatoid arthritis (RA) management. Heterogeneity of respective patient-reported outcome measures (PROMs) challenges direct comparisons between their results. This study aimed to standardize reporting of such PROMs measuring functioning in RA to facilitate comparability. Methods: Common Item Non-Equivalent Groups Design (NEAT) with the Health Assessment Questionnaire (HAQ) as a common scale across data sets from various countries (incl. UK, Turkey and Germany) to establish a common metric. Other PROMs included are the Physical Function items of the Multidimensional Health Assessment Questionnaire (MDHAQ), Disabilities of Arm, Shoulder and Hand (DASH), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), World Health Organization Disability Assessment Schedule Version 2.0 (WHODAS 2.0), and four short forms (20, 10, 6, and 4 physical function items) from the Patient-Reported Outcomes Measurement Information System (PROMIS). As the HAQ includes mobility, self-care and domestic life items, this study focuses on these three domains. PROMs were described using Standard Error of Measurement (SEM) and Smallest Detectable Difference (SDD). Rasch Measurement model was used to create the common metric. Results: Range of SEM is 0.2 (MDHAQ) to 7.4 (SF36-PF). SDD revealed a range from 9.7 \% (WOMAC-RAT) to 33.5 \% (WHODAS-PF). PROMs co-calibration revealed fit to the Rasch measurement model. A transformation table was developed to allow exchange between PROMs scores. Discussion: Scores between the Daily Activity PROMs commonly used in RA can now be compared. Factors such as SEM and SDD help determine choice of PROM in clinical practice and research.}, language = {en} }