@article{ProdingerHammondTennantetal.2019, author = {Prodinger, Birgit and Hammond, A. and Tennant, A. and Prior, Y. and Tyson, S.}, title = {Revisiting the disabilities of the arm, shoulder and hand (DASH) and QuickDASH in rheumatoid arthritis}, series = {BMC Musculoskeletal Disorder}, volume = {20}, journal = {BMC Musculoskeletal Disorder}, number = {1}, pages = {41}, year = {2019}, abstract = {Background Limitations in upper limb functioning are common in Musculoskeletal disorders and the Disabilities of the Arm, Shoulder and Hand scale (DASH) has gained widespread use in this context. However, various concerns have been raised about its construct validity and so this study seeks to examine this and other psychometric aspects of both the DASH and QuickDASH from a modern test theory perspective. Methods Participants in the study were eligible if they had a confirmed diagnosis of Rheumatoid Arthritis (RA). They were mailed a questionnaire booklet which included the DASH. Construct validity was examined by fit to the Rasch measurement model. The degree of precision of both the DASH and QuickDASH were considered through their Standard Error of Measurement (SEM). Results Three hundred and thirty-seven subjects with confirmed RA took part, with a mean age of 62.0 years (SD12.1); 73.6\% (n = 252) were female. The median standardized score on the DASH was 33 (IQR 17.5-55.0). Significant misfit of the DASH and QuickDASH was observed but, after accommodating local dependency among items in a two-testlet solution, satisfactory fit was obtained, supporting the unidimensionality of the total sets and the sufficiency of the raw (ordinal or standardized) scores. Conclusion Having accommodated local response dependency in the DASH and QuickDASH item sets, their total scores are shown to be valid, given they satisfy the Rasch model assumptions. The Rasch transformation should be used whenever all items are used to calculate a change score, or to apply parametric statistics within an RA population. Significance and innovations Most previous modern psychometric analyses of both the DASH and QuickDASH have failed to fully address the effect of a breach of the local independence assumption upon construct validity. Accommodating this problem by creating 'super items' or testlets, removes this effect and shows that both versions of the scale are valid and unidimensional, as applied with a bi-factor equivalent solution to an RA population. The Standard Error of Measurement of a scale can be biased by failing to take into account the local dependency in the data which inflates reliability and thus making the SEM appear better (i.e. smaller) than the true value without bias.}, language = {en} } @article{ProdingerCoenenHammondetal.2020, author = {Prodinger, Birgit and Coenen, M and Hammond, A and K{\"u}{\c{c}}{\"u}kdeveci, AA and Tennant, A}, title = {Scale-Banking for Patient Reported Outcome Measures (PROMs) Measuring Functioning in Rheumatoid Arthritis: A Daily Activities Metric}, series = {Arthritis Care \& Research}, volume = {Online ahead of print}, 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. Keywords: Common metric; DASH; Disability and Health; HAQ; International Classification of Functioning; Multidimensional HAQ; PROMIS-SF; Rasch measurement model; Scale banking; WHODAS 2.0; WOMAC.}, language = {en} } @article{ProdingerCoenenHammondetal.2022, author = {Prodinger, Birgit and Coenen, Michaela and Hammond, Alison and K{\"u}{\c{c}}{\"u}kdeveci, Ay{\c{s}}e A. and Tennant, Alan}, title = {Scale Banking for Patient-Reported Outcome Measures That Measure Functioning in Rheumatoid Arthritis: A Daily Activities Metric}, series = {Arthritis Care \& Research}, volume = {74}, journal = {Arthritis Care \& Research}, number = {4}, pages = {579 -- 587}, year = {2022}, abstract = {Objective Functioning is an important outcome for the management of rheumatoid arthritis (RA). 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 nonequivalent group design with the Health Assessment Questionnaire (HAQ) as a common scale across data sets from various countries (including the UK, Turkey, and Germany) to establish a common metric was used. Other PROMs included are the physical function items of the Multidimensional HAQ (MDHAQ), the Disabilities of the Arm, Shoulder, and Hand questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the World Health Organization Disability Assessment Schedule II (WHODAS II), the Medical Outcomes Study Short Form 36 (SF-36) health survey, and 4 short forms (20, 10, 6, and 4 physical function items) from the Patient-Reported Outcomes Measurement Information System. As the HAQ includes mobility, self-care, and domestic life items, this study focuses on these 3 domains. PROMs were described using standard error of measurement (SEM) and smallest detectable difference (SDD). A Rasch measurement model was used to create the common metric. Results The range of the SEM was 0.2 (MDHAQ) to 7.4 (SF-36 health survey physical functioning domain). The SDD revealed a range from 9.7\% (WOMAC rating scale) to 33.5\% (WHODAS physical functioning domain). PROMs co-calibration revealed fit to the Rasch measurement model. A transformation table was developed to allow exchange between PROM scores. Conclusion Scores between the daily activity PROMs commonly used in RA can now be compared. Factors such as SEM and SDD help to determine the choice of a PROM in clinical practice and research.}, 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} }