Measurement Properties of the Patient-Specific Functional Scale and Its Current Uses: An Updated Systematic Review of 57 Studies Using COSMIN Guidelines

Abstract

Objective To systematically review measurement properties, including acceptability, feasibility, and interpretability, and current uses of the Patient-Specific Functional Scale (PSFS). Design Systematic review of a patient-reported outcome measure using the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) guidelines. Literature Search We searched 11 databases from January 2010 to July 2020 for articles on measurement properties or use of PSFS. Study Selection Criteria Published primary articles without language restrictions. Data Synthesis Two independent reviewers screened all records, extracted data, and performed risk of bias assessments using COSMIN guidelines. We qualitatively synthesized findings for each measurement property in musculoskeletal and nonmusculoskeletal conditions, and 2 reviewers independently performed Grading of Recommendations Assessment, Development and Evaluation assessments. This study was preregistered with the Open Science Framework ( https://doi.org/10.17605/OSF.IO/42UZT ). Results Of the 985 articles screened, we included 57 articles on measurement properties and 255 articles on the use of PSFS. The PSFS had sufficient test-retest reliability in musculoskeletal (22 studies, 845 participants, low-to-moderate certainty) and nonmusculoskeletal conditions (6 studies, 197 participants, very low certainty), insufficient construct validity as a measure of physical function (21 studies, 2 945 participants, low-to-moderate certainty), and sufficient responsiveness (32 studies, 13 770 participants, moderate-to-high certainty). The standard error of measurement ranged from 0.35 to 1.5. The PSFS was used in 87 unique health conditions, some without prior evidence of validity. Conclusion The PSFS is an easy-to-use, reliable, and responsive scale in numerous musculoskeletal conditions, but the construct validity of PSFS remains uncertain. Further study of the measurement properties of the PSFS in nonmusculoskeletal conditions is necessary before clinical use. J Orthop Sports Phys Ther 2022;52(5):262–275. Epub: 05 Feb 2022. doi:10.2519/jospt.2022.10727

Measurement Properties of the Patient-Specific Functional Scale in Rehabilitation for Patients With Stroke: A Prospective Observational Study

“…In this study, the SEM accounts for the possibility that a change of 0.70 point may be due to random error. This finding is consistent with previous studies of patients with musculoskeletal disorders (SEM = 0.35–1.50) 19 and older patients in an acute care setting with and without cognitive impairment (SEM = 0.78 and 0.83). 23 …”

“…Eighty percent of the PSFS items were classified as activities and participation in the ICF, which is less than the number in this domain in a study on musculoskeletal disorders (median = 95%). 19 Individuals with subacute stroke may be more concerned about their impairments and sudden loss of function than individuals with musculoskeletal disorders may be. 53 In patients with traumatic brain injury and dizziness and balance problems, the PSFS items were classified as 65% activities and participation and 31% body functions.…”

“…The relative reliability (ICC = 0.81) is consistent with PSFS studies in patients with musculoskeletal disorders (ICC = 0.55–0.98). 19 Patients included in our study were admitted to rehabilitation ≤180 days after the stroke onset when poststroke recovery is rapid. 55 , 56 In our research, the PSFS mean score was 0.25 point higher at retest than at test, which indicates an improvement for some of the participants over 48 hours.…”

“…Pathak et al 19 used Consensus-Based Standards for Selecting Health Measurement Instruments (COSMIN) guidelines to assess measurement properties of the PSFS in a systematic review and found sufficient measurement properties in musculoskeletal disorders and some nonmusculoskeletal disorders. However, the authors emphasized the PSFS needs further evaluation before clinical use in health conditions such as stroke.…”

“… 22 Although this demonstrates the potential to use patient-specific outcome measurements in stroke rehabilitation, the measurement properties of the PSFS have not been established in this diagnostic group. 10 , 19 …”