Development of a Patient-Reported Outcomes Measurement Information System (PROMIS®) short form for measuring physical function in geriatric rehabilitation patients

Abstract

Purpose To develop and test the validity of a Patient-Reported Outcomes Measurement Information System (PROMIS®) short form for measuring physical function of geriatric rehabilitation patients. Methods Experts selected items from the Dutch-Flemish PROMIS v1.2 Physical Function (PROMIS-PF) item bank and proposed new items to develop the PROMIS-PF short form for geriatric rehabilitation (PROMIS-PF-GR). Patients evaluated its content validity. Structural validity was assessed by evaluating unidimensionality (confirmatory, exploratory, and bi-factor analyses [criterion: Omega H > 0.80 and ECV > 0.60]), local independence (criterion: residual correlation < 0.20) ,and monotonicity (criterion: H i -coefficient ≥ 0.30). Measurement invariance was assessed by evaluating Differential Item Functioning (DIF) between geriatric rehabilitation patients and people from the general population using ordinal logistic regression. Internal consistency was assessed by calculating Cronbach's alpha (criterion: alpha ≥ 0.70). Results Experts selected 24 items from the PROMIS-PF item bank and proposed one new item which was not included in the short form. Patients considered the 24 items relevant and containing essential information. The PROMIS-PF-GR's psychometric properties were evaluated in 207 patients (mean age ± SD, 80.0 ± 8.3 year; 58% female). The 24 items were found to be sufficiently unidimensional (Omega H = 0.82, ECV = 0.70), locally independent (98.7% item pairs), and monotone (all ≥ 0.32). Five items were flagged for DIF, but their impact on the total score was negligible. Cronbach's alpha was 0.94. Conclusion The PROMIS-PF-GR was developed from the PROMIS-PF and has good content validity, structural validity, measurement invariance, and internal consistency in Dutch geriatric rehabilitation patients. We recommend to confirm the content validity of the PROMIS-PF-GR in other countries.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

A Patient-Reported Outcomes Measurement Information System Short Form for Measuring Physical Function During Geriatric Rehabilitation: Test-Retest Reliability, Construct Validity, Responsiveness, and Interpretability

“…18 The PROMIS-PF-GR measures self-reported physical function, its content was compiled by geriatric rehabilitation patients and experts from the PROMIS physical function item bank. 9 It consists of 24 items on a 5-point Likert scale and takes between 4 and 7 minutes to complete and can be found in Supplementary Table 1. Four items address the degree to which the patients' health limits physical activities such as climbing stairs and taking a shower ("not at all" to "cannot do").…”

“…When patients were not able to complete the PROMIS-PF-GR, a research assistant read each item aloud and the patient verbally expressed his/her answer, which the research assistant filled in. 9 Raw PROMIS-PF-GR scores can be converted to T-scores, using Health Measures Scoring Service powered by the US Assessment Center. 19 The mean T-score of the general (US) population is 50 with a standard deviation (SD) of 10.…”

“…10 We developed and validated a custom PROMIS short form from the PROMIS physical function item bank with the involvement of experienced health professionals and geriatric rehabilitation patients: the 24-item PROMIS Physical Function Geriatric Rehabilitation (PROMIS-PF-GR) short form. 9 The PROMIS-PF-GR previously showed sufficient content validity, structural validity, measurement invariance, and internal consistency. 9 The objective of the current study was to test additional psychometric properties of the PROMIS-PF-GR in geriatric rehabilitation patients: test-retest reliability, measurement error, construct validity, responsiveness, and interpretability.…”

“…9 The PROMIS-PF-GR previously showed sufficient content validity, structural validity, measurement invariance, and internal consistency. 9 The objective of the current study was to test additional psychometric properties of the PROMIS-PF-GR in geriatric rehabilitation patients: test-retest reliability, measurement error, construct validity, responsiveness, and interpretability.…”

“…To overcome these shortcomings a new high quality PROM based on the Patient-Reported Outcomes Measurement Information System (PROMIS) was recently developed. 9 PROMIS is an innovative psychometrically sound and clinically meaningful measurement system of item banks for measuring domains such as fatigue, anxiety, and physical function across a wide range of medical conditions. 10e12 Each bank consists of a set of items (questions) with responses (answers) that measure the same domain (construct, in this case physical function) and whose item parameters (the item locations on the underlying metric and discriminative ability) have been established using Item Response Theory analysis.…”