Quality-of-Life Metrics Correlate With Disease Severity in Idiopathic Subglottic Stenosis.

OBJECTIVES: Idiopathic subglottic stenosis (ISGS) can have significant impacts on quality of life (QOL), but it remains unclear how patients' subjective responses correlate with objective measurement of disease severity. Peak expiratory flow percentage (PEF%) has been shown to be an effective measure of disease severity in subglottic stenosis. This study aims to identify the key QOL questions correlated with PEF% and proposes a statistical model for prediction of disease severity.

METHODS: Patients with ISGS presenting to an academic laryngologist were included retrospectively from 2012 to 2016. Peak expiratory flow percentage (age, sex, and height adjusted) was recorded for each visit, along with four validated QOL instruments (European QOL-Five Dimensions; RAND 36-Item Health Survey; Clinical COPD [Chronic Obstructive Pulmonary Disease] Questionnaire; and the Airway, Dyspnea, Voice, and Swallowing Summary Assessment). A stepwise multiple linear regression was used to identify statistically significant independent variables correlated with PEF%, and a model was built with these variables.

RESULTS: Thirty-two patients were included, with a total of 271 patient encounters. Overall scores from each of the four QOL instruments were correlated with PEF% values recorded each visit (P < 0.05). Question responses correlating most positively included overall breathlessness, difficulty catching breath, cough within the past week, dyspnea with moderate activity, perception that voice changes are restricting social life, and overall general health (all P < 0.01). A model constructed using six nonoverlapping questions yielded an adjusted R2 of 0.58.

CONCLUSION: Quality of life is correlated to PEF% in ISGS. Using a limited number of QOL questions, clinicians can predict objective worsening or improvement of disease severity, as measured by spirometry.

LEVEL OF EVIDENCE: 2b. Laryngoscope, 2017.