PURPOSE: Vocal cord dysfunction (VCD) is a difficult diagnosis to make clinically. While results of laryngoscopy are considered the gold standard, patient characteristics and spirometric testing are thought to be predictive of the disease. Our objective was to review the records of all patients who had laryngoscopy performed as part of their evaluation, to better define which patient and spirometric criteria were predictive of a diagnosis of VCD.
METHODS: For all patients, results of spirometric testing (to include methacholine challenge) were abstracted, along with clinical characteristics. In addition, three staff pulmonologists, blinded to each patient's diagnosis, were asked to use a Likert scale to grade the likelihood that flow loops were consistent with VCD. The interpretation of the laryngoscopy by the physician performing the procedure was considered the gold standard for establishing a diagnosis of VCD. All statistical analyses were performed using SPSS.
RESULTS: A total of 229 patients were included in the analysis, with 109 (48%) receiving a diagnosis of VCD by laryngoscopy. By univariate analysis, the following variables were significantly associated with VCD: FIF50% (p=0.043), FIF75% (p=0.007), FIF25/75% (p=0.004), and female gender (p=0.002). The value for FEF/FIF50% showed a trend towards significance (p = 0.06). These variables were entered into multivariate analysis, with gender (p=0.003, OR 2.4 (95% CI 1.3-3.8)) and FIF25/75% (p=0.007, OR 2.1 (1.2-3.7) maintaining a significant association with a diagnosis of VCD. On flow loop analysis by staff pulmonologists, agreement between physicians was poor (k = 0.39), and their rating of likelihood of VCD showed no significant association with this diagnosis by laryngoscopy.
CONCLUSION: We found several variables significantly associated with VCD, but predicting this diagnosis by clinical characteristics and spirometry alone remains challenging. Subjective interpretation of flow-loops by multiple staff showed poor correlation with each other, and with a diagnosis of VCD by laryngoscopy.
CLINICAL IMPLICATIONS: Further study is warranted to examine if these associated variables as described may be useful in the identification of patients with suspected VCD.
DISCLOSURE: Maura Watson, No Financial Disclosure Information; No Product/Research Disclosure Information