Cross-cultural adaptation, reliability and validity of the Turkish version of Patient-Specific Functional Scale in patients with chronic neck pain

Cross-cultural adaptation and psychometric properties of the Italian version of the Patient-Specific Functional Scale (PSFS) in subjects with shoulder pain

PURPOSE

To cross-culturally adapt the Patient-Specific Functional Scale (PSFS) into Italian and study its classic psychometric properties in subjects with shoulder pain (SP).

MATERIALS AND METHODS

The PSFS was translated into Italian and administered to 109 SP subjects. Acceptability (time to administer, floor and ceiling effects), reliability (internal consistency [Cronbach's alpha], test-retest reliability [Intraclass Correlation Coefficient (ICC)], and measurement error [Standard Error of Measurement (SEM), Minimal Detectable Change, (MDC)]), were assessed. Moreover, construct validity was investigated through a-priori hypothesis testing, comparing the PSFS with the Disability of the Shoulder, Arm and Hand (DASH) scale, 36-item Short Form Health Survey (SF-36) and Numeric Pain Rating scale (NPRS).

RESULTS

The PSFS was successfully adapted into Italian, and its acceptability was satisfied. Internal consistency was high (Cronbach's alpha = 0.925), and test-retest reliability was good (ICC = 0.866, 95% CI = 0.749-0.931). A SEM of 0.7 points and an MDC of 1.9 points were obtained. We observed moderate evidence for construct validity, with 4/6 correlations between other measures being respected.

CONCLUSION

This study provided reliability and validity of the PSFS in a sample of Italian SP subjects. Future studies should assess the responsiveness of using the PSFS as an outcome measure to capture clinical changes after treatment.

Reliability, Measurement Error, Responsiveness, and Minimal Important Change of the Patient-Specific Functional Scale 2.0 for Patients With Nonspecific Neck Pain

OBJECTIVE

The Patient-Specific Functional Scale (PSFS) is a patient-reported outcome measure used to assess functional limitations. Recently, the PSFS 2.0 was proposed; this instrument includes an inverse numeric rating scale and an additional list of activities that patients can choose. The aim of this study was to assess the test-retest reliability, measurement error, responsiveness, and minimal important change of the PSFS 2.0 when used by patients with nonspecific neck pain.

METHODS

Patients with nonspecific neck pain completed a numeric rating scale, the PSFS 2.0, and the Neck Disability Index at baseline and again after 12 weeks. The Global Perceived Effect (GPE) was also collected at 12 weeks and used as an anchor. Test-retest measurement was assessed by completion of a second PSFS 2.0 after 1 week. Measurement error was calculated using a Bland-Altman plot. The receiver operating characteristic method with the anchor (GPE) functions as the reference standard was used for calculating the minimal important change.

RESULTS

One hundred patients were included, with 5 lost at follow-up. No floor and ceiling effects were reported. In the test-retest analysis, the mean difference was 0.15 (4.70 at first test and 4.50 at second test). The ICC (mixed models) was 0.95, indicating high agreement (95% CI = 0.92-0.97). For measurement error, the upper and lower limits of agreement were 0.95 and -1.25 points, respectively, with a smallest detectable change of 1.10. The minimal important change was determined to be 2.67 points. The PSFS 2.0 showed satisfactory responsiveness, with an area under the curve of 0.82 (95% CI = 0.70-0.93). There were substantial to high correlations between the change scores of the PSFS 2.0 and the Neck Disability Index and GPE (0.60 and 0.52, respectively; P < .001).

CONCLUSION

The PSFS 2.0 is a reliable and responsive patient-reported outcome measure for use by patients with neck pain.

Measurement Properties' Evaluation of the Arabic Version of the Patient-Specific Functional Scale in Patients with Multiple Sclerosis

Purpose: The aim of this study was to assess the reliability and validity of the Arabic version of the patient-specific functional scale (PSFS-Ar) in patients with multiple sclerosis (MS) disorder. Materials and Methods: Reliability and validity were examined in patients with multiple sclerosis using a longitudinal cohort study design. One hundred (N = 100) patients with MS were recruited to examine the PSFS-Ar, test-retest reliability (using the interclass correlation coefficient model 2,1 (ICC_2,1)), construct validity (using the hypothesis testing method), and floor-ceiling effect. Results: A total of 100 participants completed the PSFS-Ar (34% male, 66% female). The PSFS-Ar showed an excellent test-retest reliability score (ICC_2,1 = 0.87; 95% confidence interval, 0.75-0.93). The SEM of the PSFS-Ar was 0.80, while the MDC₉₅ was 1.87, indicating an acceptable measurement error. The construct validity of the PSFS-Ar was 100% correlated with the predefined hypotheses. As hypothesized, the correlation analysis revealed positive correlations between the PSFS-Ar and the RAND-36 domains of physical functioning (0.5), role limitations due to physical health problems (0.37), energy/fatigue (0.35), and emotional well-being (0.19). There was no floor or ceiling effect in this study. Conclusions: The study results showed that the PSFS-Ar is a self-reported outcome measure that is useful for detecting specific functional difficulties in patients with multiple sclerosis. Patients are able to express and report a variety of functional limitations easily and effectively, as well as to measure their response to physical therapy. The PSFS-Ar is, therefore, recommended for use in Arabic-speaking countries for clinical practice and research for patients with multiple sclerosis.

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

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.

Cross-cultural adaptation and measurement properties of the Arabic version of the Patient-Specific Functional Scale in patients with lower extremity musculoskeletal disorders

PURPOSE

To cross-culturally adapt the Patient-Specific Functional Scale (PSFS) into Arabic language and to examine its measurement properties in patients with lower extremity musculoskeletal disorders.

MATERIALS AND METHODS

The original English version of the PSFS was cross-culturally adapted into modern standard Arabic language following Beaton's guidelines. Patients with lower extremity musculoskeletal disorders (N = 116) were recruited to examine the test-retest reliability, measurement error, floor and ceiling effects, and construct validity of the Arabic PSFS. Construct validity was tested by examining eight predefined correlational hypotheses.

RESULTS

Participants in the current study indicated that the Arabic PSFS was clear and understandable. The Arabic PSFS had very good test-retest reliability (ICC = 0.86) with no floor or ceiling issues. The standard error of measurement and the minimal detectable change of the Arabic PSFS were 0.64 and 1.49 points respectively indicating acceptable measurement error. The majority of the predefined construct validity hypotheses (75%) were supported by the results justifying the construct validity of the Arabic PSFS.

CONCLUSIONS

The Arabic PSFS is a comprehensible and easy to use measure. The Arabic PSFS has very good test-retest reliability, acceptable measurement error, and evidence supporting its construct validity as measure of activity limitation in patients with lower extremity musculoskeletal disorders.Implications for rehabilitationRehabilitation specialist can confidently interpret patient's score in the Arabic PSFS to represent the extent of activity limitation.Patients with unchanged clinical status will have similar scores in the Arabic PSFS with repeated administrations of the scale over time.The Arabic PSFS can be used in daily clinical practice and in research studies to measure activity limitation in Arabic-speakers with lower extremity musculoskeletal disorders.The Arabic PSFS enables rehabilitation specialist to quantify activity limitation in a way that is relevant to the culture and life style of Arabic-speakers.