Long-Term Inhaled Corticosteroid Adherence in Asthma Patients with Short-Term Adherence

Although the use of inhaled corticosteroids (ICS) in asthma is known to be overall erratic, the long-term use of ICS by patients selected during an episode of regular use is poorly documented.

In a cohort of patients with asthma regularly acquiring ICS therapy over several months, we verified whether these patients remained treated in the following 12 months. The correlates of regular ICS use over this period were investigated.

A historical cohort of patients with asthma was identified from the Echantillon généraliste de bénéficiaires national French health care reimbursement data (2007-2012). Patients (6-40 years) were selected during a regular ICS use episode, with 3 or more ICS refills within 120 days. Continuous multiple-interval measures of medication availability (CMA) were computed for the 12 months after the third dispensation, and the factors associated with a CMA value of 80% or more (adherent patients) were identified.

Among 5096 patients (42.1% children/teenagers, 48.8% females), only 24.0% had a CMA value of 80% or more (mean CMA = 54.4%) over the 12 months following the ICS selection period. Achieving a CMA value of 80% or more was primarily associated with being a child/teenager (P = .002), having more severe or less controlled asthma (P = .007), more previous dispensing of short-acting beta agonists (P < .0001), and receiving devices with 200 unit doses (P < .0001). Adherent patients had more frequent general practitioner visits (P < .0001), more distinct prescribers of respiratory therapy (P = .0002), and more frequent switches of ICS (P < .0001).

Most patients with asthma selected during an episode of regular ICS use did not maintain therapy over the following months. Adherence should be repeatedly monitored, and the reasons for discontinuation should be investigated, at prescriber and patient levels.