Quantifying Neck Fibrosis and Its Functional Implications: Development of the Neck Fibrosis Scale.

Abstract

Despite increasing recognition of the importance of functional outcomes for patients with head and neck cancer, post-treatment neck fibrosis remains poorly understood. We sought to develop and validate a patient reported outcome measure for head and neck cancer patients with neck fibrosis. Prospective multiphase cross-sectional study. To guide instrument development, we employed the World Health Organization International Classification of Functioning, Disability and Health as our conceptual framework. Items were generated using a composite strategy consisting of patient focus groups, literature review, and expert opinion from a multidisciplinary group. Candidate items were reduced through the item impact method. Preliminary psychometric properties of the finalized instrument were evaluated through measures of internal consistency, test-retest reliability, and construct validity. Four in person focus groups were held with 13 head and neck cancer patients. The process of item generation led to 221 relevant citations and 68 unique items. An additional 17 items were identified from review of existing neck disability questionnaires and expert opinion. A draft instrument with 25 candidate items was generated and reduced to its final 15-item scale using item impact method. Early psychometric testing revealed excellent internal consistency (Cronbach's alpha=0.95) and test-retest reliability [ICC=0.95]. Internal consistency at the item level was good (>0.7) for 11/15 individual items. Four separate constructs were evaluated. Three of the four constructs matched our a priori hypotheses. The Neck Fibrosis Scale demonstrates preliminary reliability and validity for discriminate use. Further research is needed to confirm dimensionality and assess responsiveness. NA Laryngoscope, 132:1015-1021, 2022.