Extrafine Versus Fine Inhaled Corticosteroids in Relation to Asthma Control: A Systematic Review and Meta-Analysis of Observational Real-Life Studies.

BACKGROUND

The particle size of inhaled corticosteroids (ICSs) may affect airway drug deposition and effectiveness.

OBJECTIVE

To compare the effectiveness of extrafine ICSs (mass median aerodynamic diameter, <2 μm) versus fine-particle ICSs administered as ICS monotherapy or ICS-long-acting β-agonist combination therapy by conducting a meta-analysis of observational real-life asthma studies to estimate the treatment effect of extrafine ICSs.

METHODS

MEDLINE and EMBASE databases were reviewed for asthma observational comparative effectiveness studies from January 2004 to June 2016. Studies were included if they reported odds and relative risk ratios and met all inclusion criteria (Respiratory Effectiveness Group/European Academy of Allergy and Clinical Immunology quality standards, comparison of extrafine ICSs with same or different ICS molecule, ≥12-month follow-up). End-point data (asthma control, exacerbations, prescribed ICS dose) were pooled. Random-effects meta-analysis modeling was used. The study protocol is published in the PROSPERO register CRD42016039137.

RESULTS

Seven studies with 33,453 subjects aged 5 to 80 years met eligibility criteria for inclusion. Six studies used extrafine beclometasone propionate and 1 study used both extrafine beclometasone propionate and extrafine ciclesonide as comparators with fine-particle ICSs. The overall odds of achieving asthma control were significantly higher for extrafine ICSs compared with fine-particle ICSs (odds ratio, 1.34; 95% CI, 1.22-1.46). Overall exacerbation rate ratios (0.84; 95% CI, 0.73-0.97) and ICS dose (weighted mean difference, -170 μg; 95% CI, -222 to -118 μg) were significantly lower for extrafine ICSs compared with fine-particle ICSs.

CONCLUSIONS

This meta-analysis demonstrates that extrafine ICSs have significantly higher odds of achieving asthma control with lower exacerbation rates at significantly lower prescribed doses than fine-particle ICSs.