Clinical value of bronchodilator response for diagnosing asthma in steroid-naïve adults

Abstract

Spirometry and testing for bronchodilator response have been recommended to detect asthma, and a bronchodilator response (BDR) of ≥12% and ≥200 mL has been suggested to confirm asthma. However, the clinical value of bronchodilation tests in newly diagnosed steroid-naïve adult patients with asthma remains unknown. We evaluated the sensitivity of BDR in FEV1 as a diagnostic test for asthma in a real-life cohort of participants in the Seinäjoki Adult Asthma Study (SAAS). In the diagnostic phase, 369 spirometry tests with bronchodilation were performed for 219 steroid-naïve patients. The fulfilment of each test threshold was assessed. According to the algorithm of the National Institute for Health and Care Excellence, we divided the patients into obstructive (FEV11/FVC<0.70) and non-obstructive (FEV1/FVC≥0.70) groups. Of the overall cohort, 35.6% fulfilled ΔFEV1≥12% and ≥200mL for the initial FEV1, 18.3% fulfilled ΔFEV1≥15% and ≥400 mL for the initial FEV1 and 36.1% fulfilled ΔFEV1≥9% of predicted FEV1 at least once. One-third (31%) of these steroid-naïve patients was obstructive (pre-bronchodilator FEV1/FVC<0.7). Of the obstructive patients, 55.9%, 26.5% and 48.5%, respectively, met the same thresholds. In multivariate logistic regression analysis, different thresholds recognized different kinds of asthma patients. In steroid-naïve adult patients, the current BDR threshold (ΔFEV1≥12% and ≥200 mL) has low diagnostic sensitivity (36%) for asthma. In obstructive patients, sensitivity is somewhat higher (56%) but far from optimal. If the first spirometry test with bronchodilation is not diagnostic but asthma is suspected, spirometry should be repeated, and other lung function tests should be used to confirm the diagnosis.

Development and validation of a predictive model combining patient-reported outcome measures, spirometry and exhaled nitric oxide fraction for asthma diagnosis

“…Our data show that baseline spirometric indices provided a moderate accuracy (FEV 1 (% pred): AUC 0.68; FEV 1 /FVC (%): AUC 0.69) to make a correct asthma diagnosis in patients complaining with chronic respiratory symptoms. This is in line with the value of low FEV 1 (% pred) and low FEV 1 /FVC (%) as predictors of a significant bronchodilator response [ 22 , 28 ]. However, spirometric indices performed better than measuring F ENO (AUC 0.56) in that regard, which is in keeping with previous studies conducted in other cohorts [ 15 , 29 ].…”

Prevalence, Diagnostic Utility and Associated Characteristics of Bronchodilator Responsiveness

“…These factors may account for the previous observation in two cohorts with adult-onset asthma that the proportion with a positive BDR test result (using the criterion of ΔFEV 1 ⩾12% and ⩾200 ml) at the time of diagnosis was 24% ( 47 ), modestly higher than the proportion observed in the present analysis for the equivalent definition. In a subsequent analysis within one of these cohorts, the proportion of steroid-naive patients with newly diagnosed asthma with a positive BDR test result (using the criterion of ΔFEV 1 ⩾12% and ⩾200 ml) increased from 36% overall to 56% if baseline obstruction (pre-BD FEV 1 /FVC <0.7) was present, indicating that the utility of BDR testing is enhanced if baseline airflow obstruction is present ( 48 ).…”

Agreement between Self-Reported and Registered Age at Asthma Diagnosis in Finland

“…The present diagnostic criteria have limitations and could be improved. 28,29 The limitations in asthma diagnosis may have affected to the completeness of the SII registers. Traditionally in several countries, asthma diagnosis is based solely on physician's empiric assessment of symptoms and objective pulmonary function tests are not always conducted.…”

“…Later if asthma progresses, these subjects may be quali ed for the reimbursement, and this potentially results in large time difference between self-reported and registered diagnoses. Delay in the physician-diagnosis may also result from the possibility that su cient diagnostic ndings are not found on the initial examination due the suboptimal sensitivity of spirometry even though asthma symptoms are present 29 . If the special asthma medication reimbursement has been granted more than once e.g., rst in childhood and again after resurfacing in adulthood, the self-report may refer to the latest reimbursement while only the rst granted reimbursement is denoted in the register.…”