Medication Adherence, Health Literacy Key to Managing Asthma, According to Review

Medication adherence and health literacy are underrecognized factors that influence the treatment of asthma, according to a review published in The Journal of Allergy and Clinical Immunology: In Practice. The review aimed to explain the impact of these 2 factors on medical treatment and go over interventions that can help address these obstacles to effectively treating difficult-to-control asthma.

According to the review, reported rates of adherence are below 50% in young children and between 30% and 70% in adults. Low adherence rates have been associated with high mortality rates, more frequent use of health care services, and higher risk of emergency medication use. Higher rates of adherence in patients with asthma have been shown to improve outcomes. The review authors cited a separate study that found that children with adherence greater than 60% displayed better control over their asthmatic symptoms.

Evidence suggests that low adherence may be a contributing factor to difficult-to-control asthma. In a study mentioned in the review, 56% of patients had difficult-to-control asthma due to poor adherence and poor inhaler technique. The same study found that 32% of patients with asthma were adherent to the correct inhaler but had unmanaged comorbidities. Another study, using electronic medication measurement (EMM) of an inhaled corticosteroid (ICS), found that only 18% of children with good adherence had poor control over their asthmatic symptoms.

Factors that could influence adherence include delayed effects of asthma medications, cost, attitude toward treatment plans, and patient motivation. The review also found that patients at the highest risk for nonadherence included elderly patients, adolescents, patients with a lower socioeconomic status, and patients with poor health literacy.

Poor health literacy can lead to patients misunderstanding or misinterpreting instructions from their doctor. The review authors noted that the National Assessment of Adult Literacy has found that only 12% of US adults had proficient health literacy, with more than one-third of adults having difficulty with simple medical tasks such as completing applications for health insurance.

“For asthma care, universal health literacy is particularly important when selecting inhaler devices, teaching inhaler use, and counseling on use of an asthma action plan as studies have demonstrated that 70% of asthma action plans were written above a sixth-grade reading level,” the authors wrote.

They cited a study showing that poor health literacy in adults with asthma who required controller therapies was associated with worse physical function, worse quality of life, and increased utilization of the emergency department (ED).

The authors acknowledged that there is limited data on improving health literacy in asthmatic patients, but 1 study showed that a 6-month intervention aimed at high-risk children with severe asthma, which addressed health literacy through weekly asthma education, resulted in a decline in hospital and ED visits.

Similar interventions to improve both adherence and health literacy are recommended to improve health outcomes for those with difficult-to-control asthma. The authors recommend that adherence interventions should be framed as shared decision-making between the patient and their physician to improve treatment planning and health outcomes over time.

Improving access to medicine may be the first step in improving adherence. The authors noted that a study found that patients provided with medication services as they are discharged from the hospital had lower odds of re-presentation to the ED within 30 days.

Behavioral interventions have produced mixed responses in recent studies, with 1 study claiming that the more components included in a behavioral intervention, the greater the impact on adherence. Another study showed no significant associations between adherence and behavioral change techniques in the broader asthma population.

A recent meta-analysis of 33 studies showed that interventions promoting ICS adherence were effective in adolescents with asthma. However, none of the studies specifically studied difficult-to-control asthma as the primary form of asthma.

A 2018 systemic review studied the impact of interventions on children with severe asthma, which differs from difficult-to-control asthma. In this study, adherence in children with asthma improved from a range of 28% to 67% to a range of 49% to 81% after attending interventions during pediatric visits, individualized care programs, EMM, an interactive website, and peak-flow predication with feedback.

This review was limited by the lack of studies of adherence interventions in children with severe or difficult-to-control asthma, heterogeneity in the definitions of asthma types or severities, and the variety of adherence assessment tools used.

Digital platforms can also be used improve adherence. In a review of digital adherence interventions for children with asthma, 87% of the interventions demonstrated an improvement in adherence and 53% demonstrated improved outcomes. However, approximately half of the studies in this review did not include children with severe or difficult-to-control asthma, limiting its usefulness within this subset of patients with asthma. The studies with higher rates of patients with moderate to severe asthma (>50%) demonstrated mixed findings, with no significant difference between the intervention and control groups.

The review authors acknowledged that more investigation into this subject was needed to draw further conclusions because the data used were primarily drawn from studies that did not specifically study adults and children with difficult-to-control asthma. The initiatives suggested in the review have limited data on their effects on improving adherence in patients with difficult-to-control asthma.

The authors concluded after their review that more evidence was needed on the effect of interventions on patients difficult-to-control asthma specifically to evaluate the effectiveness of such interventions. They also said it is imperative for clinicians to identify patients with suboptimal adherence to understand the reasons behind their behavior and implement treatment approaches that aim to improve adherence, especially for those with difficult-to-control asthma as they can be negatively impacted by low levels of adherence.

Reference

Zaeh SE, Ramsey R, Bender B, Hommel K, Mosnaim G, Rand C. The impact of adherence and health literacy on difficult-to-control asthma. J Allergy Clin Immunol Pract. 2022;10(2):386-394. doi:10.1016/j.jaip.2021.11.003