The WOUND-Q Function and Symptoms Scales for Chronic Lower Extremity Wounds: A Validation study.

OBJECTIVE: Determine the validity and reliability of the LIMB-Q scales, Function and Symptoms, in patients with chronic lower extremity wounds. APPROACH: Cognitive debriefing interviews with people with current or previous wounds were conducted to examine content validity. Scales were field-tested in an international sample of people with chronic lower extremity wounds sourced from an online platform (i.e., Prolific). Psychometric properties were examined using Rasch Measurement Theory analysis. A test-retest reproducibility study was performed, and construct validity examined. RESULTS: Content validity was established after 10 cognitive interviews. A total of 233 people with lower extremity wounds (age 19-80 years, mean 39.3) participated in the field-test. All 25 items tested demonstrated good fit to the Rasch model with ordered thresholds. One item had a fit residual outside ± 2.5, but no items had significant χ2 values after Bonferroni adjustment. Reliability was high with Person Separation Index, Cronbach alpha, and intraclass correlation coefficients values >0.8. Strong correlations were found between the Function and Symptoms scales and EQ-5D dimensions measuring similar constructs as well as the EQ-5D global score. All hypothesis for construct validity were confirmed. INNOVATION: PROMs are an important component of patient-centered care, as they capture the patient's perspective in a rigorous and reproducible way. Adding these two scales to the WOUND-Q provides a means to measure function and symptoms associated with lower extremity wounds. CONCLUSION: These new WOUND-Q scales can be used to measure outcomes important to patients with lower extremity wounds in clinical settings and research studies.

Further psychometric evaluation of the WOUND-Q: A responsiveness study.

The WOUND-Q is a modular patient-reported outcome measure (PROM) with 13 scales measuring constructs across 4 domains (i.e., wound characteristics, health related quality of life, experience of care and wound treatment). The psychometrics of the WOUND-Q were previously assessed and the 13 scales evidenced good validity and reliability. However, the responsiveness (i.e., ability to detect clinical change) of the WOUND-Q has yet to be assessed. The objective of this study was to evaluate responsiveness for 9 WOUND-Q scales that assess outcomes, in a sample of people 18 years of age or older with chronic wounds that were present for at least 3 months. This study conducted a 4 month follow-up of 421 participants who completed the WOUND-Q as part of a previous psychometric study. Participants completed an online survey answering questions about their current wound state (e.g., number, type, size, smell, drainage), anchor questions about change, as well as the WOUND-Q scales that they had completed in their initial assessment. Pre-defined hypotheses were tested with a 75% acceptance threshold indicating sufficient evidence of responsiveness. Minimally important differences (MIDs) were also calculated using both anchor-based and distribution-based methods. Of 390 invited participants, 320 provided responses, ranging in age from 19 to 84 years. Acceptance of hypotheses ranged from 60% to 100%, with only the Symptom scale not meeting the 75% threshold. The findings of this study provide evidence that the WOUND-Q can validly measure clinical change in patients with chronic wounds.

Further psychometric validation and test-retest reproducibility of the WOUND-Q.

WOUND-Q is a condition-specific patient-reported outcome measure developed for all types of chronic wounds, located anywhere on the body. To establish reliability and validity of a patient-reported outcome measure, multiple pieces of evidence are required. The purpose of this study was to examine the measurement properties of 9 of the 13 WOUND-Q scales and perform a test-retest reproducibility study in an international sample. In August 2022, we invited members of an international online community (Prolific.com) with any type of chronic wound to complete a survey containing the WOUND-Q scales, the Wound-QoL and EQ-5D. A test-retest survey was performed 7 days after the first survey. It was possible to examine the reliability and validity of eight of the nine WOUND-Q scales by Rasch Measurement Theory (RMT). To examine test-retest reproducibility intraclass correlation coefficients (ICCs), the standard error of the measurement and the smallest detectable change were calculated. In total, 421 patients from 22 different countries with 11 different types of chronic wounds took part in this study. Our analyses provided further evidence of the reliability and validity of the scales measuring wound characteristics (assessment, drainage, smell), health-related quality of life (life impact, psychological, sleep, social) and wound treatment (dressing).