A. Pathak1, S. Sharma2, A. Heinemann3, D. Ribeiro4, J.H. Abbott1
1University of Otago, Department of Surgical Sciences, Dunedin, New Zealand, 2Kathmandu University School of Medical Sciences, Department of Physiotherapy, Dhulikhel, Nepal, 3Northwestern University Feinberg School of Medicine, Department of Physical Medicine and Rehabilitation, Illinois, United States, 4University of Otago, School of Physiotherapy, Dunedin, New Zealand
Background: The International Classification of Functioning, Disability and Health (ICF) has over 1400 categories that represent a patient's functioning. It can be used as a reference to evaluate the content validity of an assessment scale. The Patient-Specific Functional Scale (PSFS) is a validated patient-reported measure used to assess physical function in people with musculoskeletal conditions. Studies report that the PSFS predominantly assess the "Activity" component of the ICF in musculoskeletal conditions.
The PSFS is also used, albeit less frequently and without prior validation, in cardiopulmonary and neurological conditions such as Chronic Obstructive Pulmonary Disease (COPD), Spinal Cord Injury (SCI), and stroke. The content validity of the PSFS in these populations is yet to be examined.
The PSFS is also used, albeit less frequently and without prior validation, in cardiopulmonary and neurological conditions such as Chronic Obstructive Pulmonary Disease (COPD), Spinal Cord Injury (SCI), and stroke. The content validity of the PSFS in these populations is yet to be examined.
Purpose: We sought to evaluate the content validity of the PSFS in participants with stroke, COPD, SCI, and musculoskeletal pain using the ICF.
Methods: In this cross-sectional study, we administered the PSFS to 161 participants in Nepal using interviews and identified 544 patient responses. We then used standard ICF linking rules to map (compare) these responses with the ICF categories. 5% (n= 27) randomly selected tasks were coded by AP with supervision from JHA and AH, 20% of activities (n= 108) was independently coded by JHA and AP. There was 95% (kappa 0.97, 95% CI 0.95 to 0.99) and 83% (kappa 0.879, 95% CI 0.833 to 0.923) agreement between AP and JHA at the chapter level and category level, respectively. Hence, the remaining 409 items were coded in a standardized manner by the principal author AP.
Results: Of 544 responses, 111, 132, 149, and 152 were from participants with stroke, SCI, COPD, and musculoskeletal pain, respectively. Seventy-four percentage (n = 405) of these tasks were self-selected while the rest were selected after prompts from interviewer. Eighty-eight percentage of participant responses (n= 479) mapped into the Activity component of the ICF. For all four patient populations, at least 83% of the responses were classified as Activity and less than 10% mapped to Body Structure and Function or Participation. Within Activity, the most common chapter was “d4 mobility” in all four patient conditions (46% to 89%).
Conclusion(s): The PSFS demonstrates strong evidence of content validity and adequately represents Activity Limitation among participants with stroke, SCI, COPD, and musculoskeletal pain.
Implications: This is the first study to map PSFS responses from four patient populations to ICF. The PSFS has strong content validity as a measure of Activity Limitation among participants with COPD, SCI, stroke, and musculoskeletal pain. Other instruments should be used alongside the PSFS to assess the Body Structure and Function, Participation, and contextual factor domains of the ICF.
Funding, acknowledgements: Anupa Pathak, is supported by the University of Otago Doctoral scholarship.
Keywords: Patient-Specific Functional Scale, ICF
Topic: Research methodology, knowledge translation & implementation science
Did this work require ethics approval? Yes
Institution: University of Otago
Committee: Human Ethics Committee-Health
Ethics number: H18/146
All authors, affiliations and abstracts have been published as submitted.
