The Ability of Patient-Symptom Questionnaires to Differentiate PVFMD From Asthma

Goals of the current study were to (1) conduct initial validation of a new Paradoxical Vocal Fold Movement Disorder Screening Questionnaire (PVFMD-SQ); (2) determine if symptom-based questionnaires can discriminate between patients with confirmed PVFMD and those with diagnosed uncontrolled asthma without clinical suspicion for PVFMD; and (3) determine if a new questionnaire with diagnostic specificity could be created from a combination of significant items on previously validated questionnaires.

This is a prospective, case-controlled study of patients with PVFMD only and asthma only, who completed five questionnaires: Dyspnea Index, Reflux Symptom Index, Voice Handicap Index-10, Sino-Nasal Questionnaire, and PVFMD-SQ. Factor analysis was completed on the new PVFMD-SQ, and the discrimination ability of selected factors was assessed by receiver operating characteristics curve. The factor with the greatest discriminatory ability was selected to create one diagnostic questionnaire, and scores for each participant were calculated to estimate how well the factor correlated with a PVFMD or asthma diagnosis. Mean scores on all questionnaires were compared to test their discriminatory ability.

Patients with PVFMD showed greater voice handicap and reflux symptoms than patients with asthma. A 15-item one-factor questionnaire was developed from the original PVFMD-SQ, with a sensitivity of 89% and specificity of 73% for diagnosing asthma versus PVFMD. The combined questionnaires resulted in four factors, none of which showed discriminatory ability between PVFMD and asthma.

This study represents the first time that a patient symptom-based screening tool has shown diagnostic sensitivity to differentiate PVFMD from asthma in a cohort of symptomatic patients.