Study Finds Key Outcome Predictors For Reducing Asthma Therapy

Stepping down asthma therapy is often avoided because of fear of exacerbation, but a better understanding of factors that predict step-down outcomes could encourage clinicians to wean patients off medications appropriately.

Asthma controlled with an inhaled corticosteroid (ICS) alone often leads to preventable exacerbations that require the addition of a long-acting β2 agonist (LABA). Experts, however, have recommended that LABA be used “for the shortest duration of time required to achieve control of asthma symptoms and discontinued, if possible, once asthma control is achieved.” Additionally, ICS pose a risk of potentially severe adverse effects, and as such, current guidelines for asthma management recommend that, after a period of symptom control, a reduction of dose and eventual cessation of ICS use should be attempted.

Nevertheless, once asthma has been controlled, clinicians are often reluctant to discontinue an add-on LABA or to reduce ICS use because of the fear that doing so will exacerbate asthma. As a result, many patients with well-controlled asthma are overmedicated.

To determine predictors of outcome after step-down in asthma therapy, a Finnish team evaluated 55 adult patients with well-controlled asthma who were being treated with ICS and LABA. Step-down was done in 6-week intervals starting with discontinuation of LABAs, followed by halving the ICS dose, and finally, by total ICS cessation. Patients who suffered an exacerbation after one step in the procedure were not subjected to the following step. Results of this study are reported in the August 2016 issue of Respiratory Medicine.

Findings from this step-down procedure indicated that, although LABA cessation and the halving of the ICS dose were usually well tolerated, total cessation of ICS often led to an asthma exacerbation. More specifically, 4 of 55 patients (7%) had an exacerbation after LABA cessation, and 4 of 25 (16%) had one after the ICS dose was cut in half. In contrast, 21 of 46 (46%) had an exacerbation after final cessation of ICS. In all patients who had an exacerbation, however, the episode could be managed on an outpatient basis.

The team also assessed the predictive efficacy of Juniper’s asthma control questionnaire (ACQ), ambulatory peak flow monitoring, spirometry, and hypertonic saline challenge. Results indicated that the following findings could predict a successful outcome after step-down from combination therapy:

  • ACQ score < 0.29 (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.05—5.05)
  • ACQ without spirometry < 0.15 (OR 2.17; CI 0.96—4.90)
  • FEV1 > 96% of predicted (OR 2.18; CI 1.03—4.61)

In contrast, cough responsiveness to saline, bronchoconstrictive responsiveness to saline, and peak flow variation were not found to be associated with outcome.

In light of these findings, the team concluded that asthma control assessment by spirometry and a validated questionnaire (ie, Juniper’s ACQ) can help to predict the outcome of a step-down in asthma therapy. They also determined that while combination therapy can often be safely reduced in patients with well-controlled asthma, total cessation of ICS must be considered carefully.