Multicenter Development and Validation of the Vocal Cord Paralysis Experience (CoPE), a Patient-Reported Outcome Measure for Unilateral Vocal Fold Paralysis–Specific Disability

Abstract

Unilateral vocal fold paralysis (UVFP) is a common and life-changing complication of cancer, trauma, and an estimated 500 000 head, neck, and chest surgeries performed annually in the US, among other causes (eg, idiopathic). Consequent disabilities are profound and often permanent and can include severe voice, swallowing, and breathing dysfunction and concomitant anxiety, isolation, and fear. Physiological measures often correlate poorly with patient-reported disability. The measure described herein was designed to be a comprehensive, psychometrically sound UVFP-specific patient-reported outcome measure (PROM) for use in clinical trials or at point of care. To evaluate the reliability and validity of the CoPE (vocal Cord Paralysis Experience) PROM in a nationally representative sample for both clinical and research use. This survey validation study was performed at 34 tertiary care centers across the US and included English-speaking adults with unilateral vocal fold immobility confirmed via laryngoscopy. Reliability (internal consistency, alternate form, and test-retest) and validity (convergent and known-group). In total, 613 patients (mean [SD] age, 58 [15.3] years; 394 [64.5%] women) were recruited, and 555 (92.3%) completed surveys for all time points. Internal consistency was high in the overall 22-item PROM and psychosocial, swallow, and voice subscales (Cronbach α > 0.91). Intraclass correlations for individuals between the baseline and 2-week administrations were moderate for the overall score and subscales (intraclass correlations range, 0.66-0.80). There were significant differences between the online and 2-week paper administrations for the overall score and voice and psychosocial subscales (overall scale mean: 54.4 [95% CI, 49.7-59.1] vs 48.9 [95% CI, 43.7-54.0] at 2 weeks). The confirmatory model was found to be suitably fitted based on average r2 values 0.5 or greater for subscale and overall scores. Correlations between subscales and existing PROMs (Voice-Related Quality of Life, Eating Assessment Tool, and Communication Participation Item Bank) were all greater than 0.69, and mean PROM subscale scores were significantly different across known quartiles of existing PROMs. The findings of this survey validation study suggest that the CoPE PROM could serve as a psychometrically sound, comprehensive measure of UVFP-attributed disability suitable for use in clinical and research settings to assess within-person changes. The results will inform a user manual to facilitate use in clinical trials comparing the effectiveness and durability of treatments including behavioral (speech therapy), temporary (eg, injection augmentation), and permanent surgical treatments for UVFP.