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Rasch analysis of the Patient Rated Elbow Evaluation questionnaire.

Vincent JI, MacDermid JC, King GJ, Grewal R - Health Qual Life Outcomes (2015)

Bottom Line: All three subscales of the PREE were well targeted and had high reliability (PSI >0.80).The three subscales of the PREE appear to be robust when tested against the Rasch model when subject to a few alterations.The value of changing the 0-10 format is questionable given its widespread use; further Rasch-based analysis of whether these findings are stable in other samples is warranted.

View Article: PubMed Central - PubMed

Affiliation: Roth│McFarlane Hand and Upper Limb Centre, St. Joseph's Healthcare London, Room DB 222, 268 Grosvenor Road, London, ON, N6A 4 L6, Canada. jisrael2@uwo.ca.

ABSTRACT

Background: The Patient Rated Elbow Evaluation (PREE) was developed as an elbow joint specific measure of pain and disability and validated with classical psychometric methods. More recently, Rasch analysis has contributed new methods for analyzing the clinical measurement properties of self-report outcome measures. The objective of the study was to determine aspects of validity of the PREE using the Rasch model to assess the overall fit of the PREE data, the response scaling, individual item fit, differential item functioning (DIF), local dependency, unidimensionality and person separation index (PSI).

Methods: A convenience sample of 236 patients (Age range 21-79 years; M: F- 97:139) with elbow disorders were recruited from the Roth│McFarlane Hand and Upper Limb Centre, London, Ontario, Canada. The baseline scores of the PREE were used. Rasch analysis was conducted using RUMM 2030 software on the 3 sub scales of the PREE separately.

Results: The 3 sub scales showed misfit initially with disordered thresholds on17 out of 20 items), uniform DIF was observed for two items ("Carrying a 10lbs object" from specific activities subscale for age group; and "household work" from the usual activities subscale for gender); multidimensionality and local dependency. The Pain subscale satisfied Rasch expectations when item 2 "Pain - At rest" was split for age group, while the usual activities subscale readily stood up to Rasch requirements when the item 2 "household work" was split for gender. The specific activities subscale demonstrated fit to the Rasch model when sub test analysis accounted for local dependency. All three subscales of the PREE were well targeted and had high reliability (PSI >0.80).

Conclusion: The three subscales of the PREE appear to be robust when tested against the Rasch model when subject to a few alterations. The value of changing the 0-10 format is questionable given its widespread use; further Rasch-based analysis of whether these findings are stable in other samples is warranted.

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Related in: MedlinePlus

Showing disordered threshold for item 5 “How often do you have pain?” of the pain subscale a Before rescoring, b After rescoring
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Fig1: Showing disordered threshold for item 5 “How often do you have pain?” of the pain subscale a Before rescoring, b After rescoring

Mentions: To improve the overall fit to the Rasch model items 3, 4, and 5 were rescored to a 0–7 scale. (See Table 4; Fig 1) Then item 2 was split for age group; this resulted in excellent item fit and non-significant item trait interaction. Uniform DIF (Age group) for item 2 was not evident Table 5. Unidimensionality was observed and no local dependency was present Table 6. The reliability improved to be 0.90. (See Table 1; final analysis) In spite of some floor and ceiling effects observed, targeting was also good as indicated by the person item threshold map. (See Fig. 2a) This implies that this sub scale has a good coverage for elbow disorders related pain. Hence, this was accepted as the final model.Table 4


Rasch analysis of the Patient Rated Elbow Evaluation questionnaire.

Vincent JI, MacDermid JC, King GJ, Grewal R - Health Qual Life Outcomes (2015)

Showing disordered threshold for item 5 “How often do you have pain?” of the pain subscale a Before rescoring, b After rescoring
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4482053&req=5

Fig1: Showing disordered threshold for item 5 “How often do you have pain?” of the pain subscale a Before rescoring, b After rescoring
Mentions: To improve the overall fit to the Rasch model items 3, 4, and 5 were rescored to a 0–7 scale. (See Table 4; Fig 1) Then item 2 was split for age group; this resulted in excellent item fit and non-significant item trait interaction. Uniform DIF (Age group) for item 2 was not evident Table 5. Unidimensionality was observed and no local dependency was present Table 6. The reliability improved to be 0.90. (See Table 1; final analysis) In spite of some floor and ceiling effects observed, targeting was also good as indicated by the person item threshold map. (See Fig. 2a) This implies that this sub scale has a good coverage for elbow disorders related pain. Hence, this was accepted as the final model.Table 4

Bottom Line: All three subscales of the PREE were well targeted and had high reliability (PSI >0.80).The three subscales of the PREE appear to be robust when tested against the Rasch model when subject to a few alterations.The value of changing the 0-10 format is questionable given its widespread use; further Rasch-based analysis of whether these findings are stable in other samples is warranted.

View Article: PubMed Central - PubMed

Affiliation: Roth│McFarlane Hand and Upper Limb Centre, St. Joseph's Healthcare London, Room DB 222, 268 Grosvenor Road, London, ON, N6A 4 L6, Canada. jisrael2@uwo.ca.

ABSTRACT

Background: The Patient Rated Elbow Evaluation (PREE) was developed as an elbow joint specific measure of pain and disability and validated with classical psychometric methods. More recently, Rasch analysis has contributed new methods for analyzing the clinical measurement properties of self-report outcome measures. The objective of the study was to determine aspects of validity of the PREE using the Rasch model to assess the overall fit of the PREE data, the response scaling, individual item fit, differential item functioning (DIF), local dependency, unidimensionality and person separation index (PSI).

Methods: A convenience sample of 236 patients (Age range 21-79 years; M: F- 97:139) with elbow disorders were recruited from the Roth│McFarlane Hand and Upper Limb Centre, London, Ontario, Canada. The baseline scores of the PREE were used. Rasch analysis was conducted using RUMM 2030 software on the 3 sub scales of the PREE separately.

Results: The 3 sub scales showed misfit initially with disordered thresholds on17 out of 20 items), uniform DIF was observed for two items ("Carrying a 10lbs object" from specific activities subscale for age group; and "household work" from the usual activities subscale for gender); multidimensionality and local dependency. The Pain subscale satisfied Rasch expectations when item 2 "Pain - At rest" was split for age group, while the usual activities subscale readily stood up to Rasch requirements when the item 2 "household work" was split for gender. The specific activities subscale demonstrated fit to the Rasch model when sub test analysis accounted for local dependency. All three subscales of the PREE were well targeted and had high reliability (PSI >0.80).

Conclusion: The three subscales of the PREE appear to be robust when tested against the Rasch model when subject to a few alterations. The value of changing the 0-10 format is questionable given its widespread use; further Rasch-based analysis of whether these findings are stable in other samples is warranted.

Show MeSH
Related in: MedlinePlus