The Use of Questionnaires in Diagnosis and Management of ILO/VCD
Laryngoscopy represents the gold standard for diagnosis of ILO/VCD. However, only a subset of clinicians specialized in the management of laryngeal disorders are trained in performing this procedure. Furthermore, ILO/VCD changes are frequently seen only during an acute flare or if provoked by exercise, hyperventilation and other factors.
The use of validated clinical questionnaires represent a reasonable initial step in suspected ILO/VCD. Moreover, some questionnaires can be used to quantify symptom severity and response to treatment over time. Potential roles for questionnaires are therefore dependent on different clinical and research settings. Questionnaires are therefore useful for screening in the primary care setting and arguably to decide about treatment in a subspecialty clinic in patients who have a high clinical suspicion for ILO/VCD – but indeterminate laryngoscopy findings or refused laryngoscopy.
VCD/ILO specific questionnaires
Pittsburgh Vocal Cord Dysfunction (VCD) Index
The Pittsburgh VCD Index (PVCDI) was developed to try to distinguish asthma from VCD/ILO in adults. It contains 4 questions and a sensitivity of 83% and specificity of 95% for diagnosis of VCD/ILO has been reported. Furthermore, the PVCDI may have reasonable sensitivity (~70%) in diagnosing co-existing VCD/ILO in patients with asthma and could be used both in clinical and research settings.
Vocal Cord Dysfunction (VCD) Questionnaire
The VCD questionnaire (VCDQ) was developed to monitor symptoms over time and/or response to VCD/ILO treatment in adults. It contains 12 questions and can be used both in clinical and research settings. The VCDQ was not designed to screen for the presence of VCD/ILO.
Exercise-Induced Laryngeal Obstruction Dyspnea Index (EILODI)
EILODI was developed in patients aged 12-21 years with confirmed exercise-induced laryngeal obstruction (EILO). It contains 12 questions and is designed to assess response to therapy or change in symptom intensity. The performance of co-existing asthma did not significantly impact the questionnaire’s performance. The EILODI was not designed to screen patients for the presence of EILO. It can be used both in clinical and research settings.
Non-VCD/ILO Specific Questionnaires
Dyspnea Index (DI)
The Dyspnea Index was developed to measure symptom severity caused by a variety of conditions originating in the upper airway, including structural, neurologic, and functional causes in adults. It contains 10 questions and can be used as a treatment outcome measure, both in clinical and research settings.
Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ)
Laryngeal hypersensitivity is an umbrella term that includes 4 conditions: VCD/ILO, chronic cough, muscle tension dysphonia and globus pharyngeus. The LHQ was developed to detect and quantify the severity of laryngeal hypersensitivity symptoms in adults and contains 14 questions that can be used to quantify the patient experience of laryngeal discomfort and to measure change over time. The questionnaire also discriminates between healthy (a cut-off of 17 points) and patients with laryngeal hypersensitivity syndromes. No sensitivity or specificity data for the test have been reported. It can be used both in clinical and research settings.