Medication adherence and the risk of severe asthma exacerbations: a systematic review

Abstract

The benefits of drug therapy for asthma have been well established, but adherence to treatment is poor, and this might be associated with an increased risk of asthma exacerbations. The aim of this study was to review the literature on the association between adherence to asthma controller treatment and risk of severe asthma exacerbations in children and adults.A systematic literature search was performed in PubMed, Embase and Web of Science, from inception until January 2014. Studies were included if data on the association between medication adherence and severe asthma exacerbations were presented. Quality was assessed using a modified version of the Newcastle-Ottawa Scale.The search yielded 2319 unique publications, of which 23 met the inclusion criteria and underwent data extraction and quality scoring. High levels of heterogeneity across studies with regard to adherence and exacerbation measurements, designs and analysis precluded a formal meta-analysis. Although effect measures varied widely, good adherence was associated with fewer severe asthma exacerbations in highquality studies.Good adherence tended to be associated with lower risk of severe asthma exacerbations. Future studies should use standardised methodology to assess adherence and exacerbations, and should consider inhaler competence.@ERSpublications High-quality studies indicated that better adherence is associated with fewer severe asthma exacerbations

Brand and generic use of inhalation medication and frequency of switching in children and adults: A population-based cohort study

“…From adherence studies on chronic medication, it is known that adherence is the highest upon treatment initiation, but decreases rapidly in the first 3-6 months [28][29][30]. MPR calculations and fixed time periods are not ideal to calculate adherence; however, it is a common method used in database studies to estimate drug use [31]. Differences in adherence before and after switch were observed in users of budesonide and beclomethasone, where the median MPR was different after switch, direction depending on the time period, type of medication, and type of switch.…”

Inhalation therapy in the next decade: Determinants of adherence to treatment in asthma and COPD

“…Current evidence from studies in children and adults suggests that inadequate health literacy is an important key barrier to asthma knowledge [80,81]. Hence, focusing on nonadherence related to health literacy in asthmatic patients may yield benefits in term of both human suffering and economic costs.…”

Evaluation of factors affecting adherence to asthma controller therapy in chest clinics in a sub-Saharan African setting: a cross-sectional study

“…Adherence which is defined as the patient's behaviors regarding recommendations from a health care provider 4 is a crucial factor contributing to the control of asthma. A recent systematic review showed that good adherence to asthma medication is associated with low risk of severe exacerbation 5 . On the contrary, it has been demonstrated that low rate of adherence to asthma controller therapy is a risk factor for admission to the hospital, near-fatal asthma exacerbations, and death from asthma 6,7 .…”

“…Less than 50% of children are adherent to this treatment while in the adult population, the adherence is also low with a highly variable range from 30 to 70% depending on the area where the studies have been conducted 5 . In Nigeria, Desalu et al found that 69.3% of their study population had uncontrolled asthma and there was a strong association between uncontrolled asthma and lack of adherence to inhaled corticosteroids 10 .…”