Patient-Reported Quality-of-Life Outcome Measure After Parotidectomy.

Abstract

Importance: There is a lack of reliable, patient-reported quality-of-life (QOL) instruments to address the multidimensional nature of patient-centered outcomes for patients undergoing parotidectomy. The Parotidectomy Quality of Life Index is a new 35-item validated patient-reported outcome instrument specific to recovery after parotidectomy.

Objective: To establish and validate a comprehensive English-language patient-reported QOL instrument specific to parotidectomy.

Design, setting, and participants: This survey study was conducted in 2 phases: first, in a single-institution cohort (October 12, 2021, to March 7, 2022), and second, as an anonymous web-based survey enrolled via printed promotional brochures and social media platforms (March 13 to July 31, 2023). Inclusion criteria were age at least 18 years and parotidectomy within the last year. For test-retest reliability, a subset of phase II participants volunteered to answer the survey a second time within 2 weeks. Data were analyzed from March 8, 2022, to November 3, 2023.

Main outcomes and measures: Item rankings from phase I participants were used to narrow the original 61-item survey down to 45 items in the phase II survey. To assess construct validity, an exploratory factor analysis was performed. Cronbach α and pairwise Pearson correlation coefficients were used to measure internal consistency, reliability, and redundancy. Test-retest reliability was evaluated using intraclass correlation coefficients.

Results: Phase I enrolled 38 individuals, of whom 30 completed the survey (15 women [60%]; 21 participants [84%] aged >40 years). Phase II enrolled 342 participants, of whom 317 completed the survey (305 women [89%]; 284 participants [83%] aged >40 years). A total of 42 items across 7 domains were selected based on exploratory factor analysis. After Cronbach α and pairwise correlation analysis, 33 items across 6 multi-item domains and 2 standalone items were incorporated into the final QOL instrument. Cronbach αs for each of the final 6 domains were at least 0.77, suggesting excellent internal validity. Pairwise correlations did not show strong correlations (ie, none ≥0.80), suggesting minimal redundancy between domains. Younger age was significantly associated with a lower global score. Participants with malignant tumors scored lower on 4 of the 6 multi-item domains. Test-retest reliability coefficients for the domains ranged from 0.82 to 0.93, indicating very good reproducibility over a 2-week interval.

Conclusions and relevance: These findings suggest the Parotidectomy Quality of Life Index demonstrated excellent internal validity and test-retest reliability. With further external validation, this instrument may provide opportunity for quality improvement in clinical practice and has potential as a key patient-reported outcome in future parotidectomy clinical trials.