High risk factors affecting the prognosis of cough variant asthma: analysis of 73 cases

Abstract

Objective To explore the high risk factors affecting the prognosis of patients with cough variant asthma (CVA). Methods From the standardized follow-up database of patients with chronic cough, we retrieved the data of patients with CVA followed up for more than 5 years with complete clinical and prognostic data. According to the demand of medications, the patients were divided into low- and high-demand treatment groups for comparative analysis of the clinical characteristics and their correlation with the outcomes of the patients. Logistic regression was used to identify the risk factors associated with the prognosis of the patients, and the discriminant function was used to determine the cut-off values of the specific risk factors for predicting the patients' outcomes. Results We retrieved the data of 73 eligible patients from the database. Thirty-eight (52.1%) of the patients did not experience any treatment with inhaled corticosteroids (ICS) in 5 years (the median follow-up time) following a short-term treatment. The low- and high-demand treatment groups differed significantly in PD20, number of laryngopharyngeal signs and percentage of patients with laryngopharyngeal signs. PD20 and lymphoid follicle hyperplasia and congestion of the posterior pharyngeal wall showed significant correlations with the outcomes of the patients, and the former two factors were identified as risk factors by the logistic regression model. Discriminant function analysis showed that 74% of the patients were grouped correctly for the outcomes based on these two factors. Conclusion A substantial portion of CVA patients do not require further treatment in the next 5 years following a short-term treatment. The CVA patients are exposed to co-existing risks of over-treatment and inadequate treatment, and those with a high PD20 level and a low level of lymphoid follicle hyperplasia in the posterior pharyngeal wall have a low demand of further treatment.

Keywords

• cough variant asthma
• prognosis
• chronic cough