அலர்ஜி & தெரபி ஜர்னல்

சுருக்கம்

Effect of Inhaled Corticosteroid Therapy Step-Down and Dosing Regimen on Measures of Asthma Control

David Price, Alison Chisholm, Elizabeth V Hillyer, Annie Burden, Julie von Ziegenweidt, Henrik Svedsater and Peter Dale

Background: Asthma guidelines recommend stepping down therapy to the lowest dose that maintains asthma control.

Objective: We sought to evaluate the effect of dosing frequency and baseline patient and treatment-related factors on database markers of asthma control after inhaled corticosteroid (ICS) dose step-down.

Methods: This retrospective observational study evaluated primary care patients (4-80 years old) with asthma prescribed twice-daily (BD) ICS (n=26,834) or ICS/long-acting β-agonist (LABA; n=20,814) for ≥ 1 year before ≥ 50% step-down in ICS dose, when they were switched to once-daily (QD) or remained on BD therapy. Study endpoints included exacerbations (oral corticosteroid prescription, unscheduled asthma-related hospital attendance, or general practice consultation for lower respiratory tract infection) and medication adherence.

Results: Significant improvements in most endpoints were recorded during the year after step-down, as compared with the prior year (baseline). The proportion of patients with no exacerbation during the baseline year vs. the year after step-down was as follows (p<0.001 for all comparisons): QD ICS cohort (73% baseline vs. 81% after step-down); BD ICS cohort (67% vs. 77%); QD ICS/LABA cohort (60% vs. 64%); BD ICS/LABA cohort (55% vs. 65%). Adherence improved significantly after step-down for all cohorts, most markedly for QD cohorts; and the average daily ICS dose as consumed by patients was higher for all but the QD ICS/LABA cohort despite the reduction in prescribed dose. Factors predicting loss of asthma control after step-down for patients controlled at baseline in either or both ICS and ICS/LABA populations included obesity, smoking, comorbid rhinitis, comorbid gastroesophageal reflux disease, and, during the baseline year, ≥ 7 short-acting β-agonist prescriptions, mean consumed ICS dose of ≥ 800 μg/day, and ≥ 4 primary care consultations.

Conclusion: Stepping down therapy is a valid management option and may improve asthma-related outcomes. Some improvements may result from increased adherence, particularly among patients switched to QD therapy.