Trend of Bronchial Hyperresponsiveness to Methacholine as a Cost Predictor of Mild-to-Moderate Asthma: A Twelve-Month Survey in Teenagers.

Abstract

Patients aged 12-18 years with mild-to-moderate symptoms treated with fluticasone fumarate/vilanterol 92/22 mcg daily were retrospectively followed for 12 months. Usual spirometric parameters, BHR to methacholine (MCh), and resource consumption (visits, hospitalizations, systemic steroids and/or antibiotics courses, school days off) were assessed at recruitment (the index date) and after 6 and 12 months. Adherence to treatment was also calculated. The cost of asthma was calculated based on Italian tariffs and published papers. The trend over time in BHR and the association between response to MCh and total cost were investigated by using regression models adjusted for repeated measures. 106 teenagers (53 males, age 15.9 ± 1.6 years) were investigated. The annual cost of asthma proved significantly related to the BHR trend: every increment of a factor 10 in the response to MCh was associated with a saving of EUR 184.90 (95% CI -305.89 to -63.90). BHR was progressively optimized after 6 and 12 months in relation to the patients' compliance to treatment (≥70% of prescribed inhalation doses). the usual spirometric parameters are largely insufficient to reflect the effects of underlying persistent inflammation in milder forms of asthma in teenagers. In terms of clinical governance, the periodic assessment of non-specific BHR is the appropriate procedure from this point of view. Non-specific BHR proves a reliable procedure for predicting and monitoring the economic impact of mild-to-moderate asthma in teenagers over time.