Department of Physical Therapy Student Theses, Dissertations and Capstones

Document Type


Degree Name

Doctor of Philosophy (PhD)

Copyright Statement

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College of Health Care Sciences - Physical Therapy Department

First Advisor

M. Samuel Cheng

Second Advisor

Morey J. Kolber

Third Advisor

Mary Lou Galantino

Publication Date / Copyright Date



Context: Medical management for head and neck cancer (HNC) often includes neck dissection surgery, a side effect of which is shoulder dysfunction. There is no consensus for which patient-reported outcome measure (PRO) is most appropriate to quantify shoulder dysfunction in this population.

Objective: The aims of this research study were to: (1) use Rasch methodologies to assess construct validity and overall appropriateness of test score interpretation of Disability of the Arm, Shoulder and Hand (DASH), QuickDASH, Shoulder Pain and Disability Index (SPADI) and Neck Dissection Impairment Index (NDII) in the HNC population; (2) determine appropriateness of use of University of Washington Quality of Life (UW-QoL) shoulder subscale as a screening tool for shoulder impairment; (3) recommend a new PRO, or combination of PROs, that more accurately portrays the construct of shoulder dysfunction in the HNC population.

Design: One hundred and eight-two individuals who had received a neck dissection procedure within the past 2 weeks to 18 months completed the PROs. Rasch methodologies were utilized to address the primary aim of the study through consideration of scale dimensionality [principal components analysis, item and person fit, differential item functioning (DIF)], scale hierarchy (gaps/redundancies, floor/ceiling effects, coverage of ability levels), response scale structure, and reliability (person and item reliability and separation statistics). The secondary aim was addressed through correlational analysis of the UW-QoL (shoulder subscale), DASH, QuickDASH, SPADI and NDII.

Results: The DASH did not meet criteria for unidimensionality, and was deemed inappropriate for utilization in this sample. The QuickDASH, SPADI and NDII were all determined to be unidimensional. All scales had varying issues with person and item misfit, DIF, coverage of ability levels, gaps/redundancies, and optimal rating scale requirements. The NDII meets most requirements. All measures were found to meet thresholds for person and item separation and reliability statistics. The third aim of this study was not addressed because the NDII was determined to be appropriate for this population.

Conclusions: Rasch analysis indicates the NDII is the most appropriate measure studied for this population. The QuickDASH and SPADI are recommended with reservation. The DASH and the UW-QoL (shoulder subscale) are not recommended.


Medicine and Health Sciences | Oncology | Physical Therapy | Rehabilitation and Therapy | Statistics and Probability


head and neck cancer, item response theory, patient reported outcome measure, physical therapy, Rasch Analysis, shoulder dysfunction

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