Factors that determine the loss of control when reducing therapy by steps in the treatment of moderate-severe asthma in standard clinical practice: A multicentre Spanish study

Background: Although the clinical practice guidelines recommend continuous adjustment of asthma treatment and reducing the maintenance drugs when achieving control (step-down), there are few studies of standard clinical practice aimed at collecting information on the factors that determine step-down failure.

Objective: To determine the factors that determine step-down failure in standard clinical practice of patients with moderate-severe asthma controlled by a combination of inhaled glucocorticoids and long-acting beta agonists.

Methods: A multicentre retrospective study included 374 patients with moderate-severe asthma controlled with inhaled glucocorticoids and long-acting beta agonists for whom the physician indicated a step-down in 2016.

Results: The step-down failed in 41.7% of the patients. The following factors were related to failure: greater patient age (P=.006), presence of at least 2 comorbidities (P=.016), greater severity level (severe persistent vs. moderate persistent) (P<.001), greater age at diagnosis (>40 years) (P=.045), the higher the therapeutic step before (P=.003) and after the change (P<.001), the shorter the time of improvement/control prior to the change (P=.019), lower FEV₁ (P=.001) and a poorer Asthma Control Test score or Asthma Control Questionnaire score before the step-down (P<.001). The logistic regression analysis showed a higher probability of step-down failure in the more elderly patients (OR, 0.983; 95% CI 0.969-0.997) and those with severe asthma compared to those with moderate asthma (OR, 0.537; 95% CI 0.292-0.985), as well as an increased probability of success if the patients had the disease controlled for more than 6 months (OR, 2.253; 95% CI 1.235-4.112).

Conclusion: In standard clinical practice conditions, step-down fails in a high percentage of patients, and the suggestion is to indicate step-down when the patient has had more than 6 months of disease control.