ICS Inadherence Linked to Poor Long-Term Asthma Health

Iida Vahatalo, MD

A follow-up on 12 years of asthma patient data showed those who with not-controlled asthma adhered well to their inhaled corticosteroid (ICS) therapy, but were also at great risk of worsening disease if they didn't.

The long-term assessment, presented virtually at the European Respiratory Society (ERS) 2020 Congress this week, depicted concerning risks to rapidly declining lung function among those less likely to adhere to the staple therapy in asthma maintenance regimens.

A team of Finland-based investigators, led by Iida Vahatalo, of the Department of Respiratory Medicine at the Seinajoki Central Hosptial, and Faculty of Medicine and Health Technology at Tampere University, sought to understand the associations between 12-year adherence to ICS and asthma control among patients with an adult-onset form of the respiratory disease.

They noted such ventures into decade-plus treatment adherence—and its implications—have been infrequently pursued previously.

“In short-term studies, poor adherence to ICS has been associated with worse asthma control but the association of long-term adherence and disease control remains unstudied,” they wrote.

Vahatalo and colleagues used data from the Seinajoki Adult Asthma Study (SAAS) to assess 181 adults with clinically confirmed new-onset asthma who were prescribed standard ICS therapy over a span of 2 years.

They analyzed the percentage of patients adhering to ICS individually (mcg dispensed / mcg prescribed x 100) during the follow-up. Asthma control, as per the Global Initiative for Asthma (GINA) 2010 guideline, was evaluated post-12 years of ICS prescribing.

In their observed population, 31% of patients had controlled asthma, and 69% had uncontrolled or partly controlled asthma. Patients with not-controlled asthma were more frequently male, older, and less educated. Their asthma was less frequently atopic, and was treated with higher prescription doses of ICS than that of adults with controlled asthma.

Mean adherence to ICS at 12 years was 63% among patients with controlled asthma, and 76% in those with no-controlled asthma (P = .042). Those with not-controlled asthma and lower 12-year adherence (as per <80%) reported a more rapid decline in lung function as per forced expiratory volume at 1 second (FEV1) versus those with better adherence (P = .024).

The same correlation, however, was not observed among adults with controlled asthma who varied on ICS adherence at 12 years.

Vahatalo and colleagues concluded their findings underscore the importance of recognizing adults with not-controlled asthma and poor ICS adherence early into their treatment.

“In clinical practice, careful evaluation of patient’s asthma control and adherence to treatment enhances the recognition of those patients at risk of rapid lung function decline at long-term,” they wrote.

The study, “Long-term adherence to inhaled corticosteroids and asthma control in adult-onset asthma,” was presented at ERS 2020.