Patient response to the management during the acute presentation of cough variant Asthma: Retrospective cohort study

Development and validation of a nomogram for predicting cough variant asthma diagnosis

BACKGROUND

Cough variant asthma (CVA) is a specific type of asthma characterized by chronic cough as the sole or predominant symptom. Accurate diagnosis is crucial for effective treatment, yet bronchial provocation test is not always feasible in clinical settings. To identify independent predictors of CVA diagnosis, we developed a nomogram for predicting CVA. Univariate and multivariate logistic regression analyses were employed to construct the model, and the accuracy and consistency of the prediction model were subsequently validated.

METHODS

We conducted a retrospective review of clinical data from 241 outpatients with chronic cough (≥ 8 weeks) who underwent bronchial provocation test at our hospital between January 2018 and December 2021. Patients were categorized into CVA group and Non-CVA group based on diagnostic criteria. Univariate analysis (chi-square and t-tests) was performed, followed by multivariate logistic regression to identify independent predictors. A nomogram was constructed using these predictors and validated using Bootstrap resampling (B = 200) to calculate the C-index. Additionally, receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were employed to assess the model's accuracy.

RESULTS

Of the 241 outpatients, 156 (64.7%) were diagnosed with CVA. Multivariate analysis identified several independent predictors of CVA, including cough triggered by cold air (OR = 12.493, P = 0.019), exposure to pungent odors (OR = 3.969, P = 0.002), cough phasing (OR = 4.515, P < 0.001), history of allergic rhinitis (OR = 3.231, P = 0.018), and the percentage of the predicted value of maximum mid-expiratory flow (MMEF%pred) (OR = 0.981, P = 0.039) were independent predictors of CVA. The nomogram demonstrated good discrimination (AUC = 0.829) and calibration, with a sensitivity of 75.3% and specificity of 77.6% at the optimal cutoff. The C-index was 0.920, indicating excellent model performance.

CONCLUSIONS

We successfully developed and validated a user-friendly nomogram that accurately predicted CVA diagnosis based on clinical characteristics and pulmonary function test. This nomogram model could assist clinicians in diagnosing CVA, especially in patients without bronchial provocation test or with contraindications to bronchial provocation test.

The Effects of Budesonide Inhalation Treatment on the Expression Levels of Serum IL-6, TGF-β1, and IgE and Pulmonary Function in Patients with Cough Variant Asthma and an Evaluation of Treatment Efficacy

Objective

To retrospectively study the effects of budesonide inhalation combined with conventional symptomatic treatment on serum inflammatory factor expression levels and pulmonary function in patients with cough variant asthma (CVA) and to evaluate treatment efficacy.

Methods

This retrospective cohort study included 200 patients diagnosed with CVA at the Second Hospital of Jiaxing between January 2022 and June 2023 and given conventional symptomatic treatment plus budesonide inhalation were included in this study. Patients were divided into a no remission group, a partial remission group and a complete remission group based on treatment effect. The expression levels of serum inflammatory factors, cough symptom scores, and small airway function indicators in the three groups of patients at different time points were compared.

Results

In the three groups of CVA patients, after receiving budesonide inhalation combined with conventional symptomatic treatment, the expression levels of serum IL-5, IL-6, IL-8, TNF-α, TGF-β1, and IgE and number of eosinophils significantly decreased (P <0.05). There were statistically significant differences in the IL-6 and TGF-β1 levels among the three groups of CVA patients at T1, T2 and T3. There were statistically significant differences in IgE levels, number of eosinophils, cough symptom scores, and small airway function indicators between T2 and T3 (P<0.05). The receiver operating characteristic (ROC) curve prediction analysis revealed significant differences in the expression of IL-6 and TGF-β1 at T1, T2, and T3.

Conclusion

Budesonide inhalation combined with conventional symptomatic treatment can significantly reduce the levels of serum inflammatory factors in patients with CVA to reduce inflammation and the allergic response, thereby reducing the cough symptom score, improving pulmonary function, and improving therapeutic efficacy. In addition, IL-6 and TGF-β1 can be used as early predictors of budesonide inhalation efficacy.