Introduction
Asthma is the most common chronic non-communicable disease in children
worldwide 1. Asthma prevalence is higher in children
in Europe (8.9%), compared to the rest of the world (7.2%)2 but varies between countries 3.
Most children with asthma achieve good disease control with maintenance
low dose inhaled corticosteroids (ICS), which are effective at
preventing most asthma hospitalisations and deaths 4.
However, some children remain poorly controlled despite being prescribed
high-dose ICS treatment, often due to poor adherence. This contributes
to suboptimal asthma control and severe attacks5; 6.
Up to half of patients attending tertiary care paediatric asthma clinics
are non-adherent (defined as taking less than 80% of their prescribed
dose)7.
The Global Initiate for Asthma (GINA) highlights that suboptimal use of
asthma treatment is a patient-specific barrier that contributes to the
burden of asthma 8. Similarly, the UK National Review
of Asthma Deaths reported that 67% of asthma deaths were avoidable, and
one of the most important avoidable factors was low ICS adherence in the
month and/or year before death 9.
Many interventions have been developed to address the issue of poor ICS
adherence in children. A meta-analysis in adults and children identified
that interventions for improving adherence in asthma can be effective10. However, the meta-analysis did not examine the
intervention characteristics e.g. content, channel of delivery and
context of the intervention, which form the three components of
behaviour change framework (3CBC11) in relation to
intervention efficacy. It is important to be able to identify
characteristics of effective interventions so that they may be applied
in practice.
Moreover, the reliability of the diagnosis of asthma and the adherence
measurement tool have not previously been used to identify high
reliability interventions. If patients are diagnosed with asthma
incorrectly, non-adherence to a treatment that is therefore unnecessary
is logical. Similarly, if adherence is overestimated in studies using
unreliable adherence measurements, then the conclusions drawn from the
studies will also be inaccurate. By investigating these factors, the
data presented in this review are likely to be more relevant to practice
as they represent a rigorous test of the intervention.
The National Institute for Clinical Excellence (NICE) has developed
guidelines intended to aid the design of adherence support for long term
conditions at any stage of the life span 12. The
guidelines apply the Perceptions and Practicalities Approach (PAPA13 E-image 1). This approach recognises that adherence
varies within the individual, over time and across treatments.
Adherence/non-adherence is best understood in terms of the interaction
between an individual and a particular treatment. It is a variable
behaviour rather than a trait characteristic. The Perceptions and
Practicalities Approach (PAPA) conceptualises adherence as including
both intentional and unintentional non-adherence.
The application of the PAPA approach to adherence interventions has the
following key features firstly, the need for a no-blame approach as
patients are often reluctant to admit to non-adherence, or to concerns
about the treatment, as they fear that this may be interpreted by the
clinician as doubting their expertise. Hence, non-adherence and the
reasons for it are often hidden. The second key feature is the need to
tailor support to address both perceptions (e.g. beliefs about
asthma and its treatment) and practicalities (e.g. clear
instructions on inhaler technique, establishing a medication routine).
Both perceptions and practicalities influence the patient’s motivation
and ability to start and continue taking the treatment. Indeed, research
in asthma has shown beliefs about ICS are often important perceptual
barriers to adherence, particularly doubts about the personal need for
regular inhaler use particularly in the absence of symptoms and concerns
about corticosteroids 14; 15.
This systematic review aims to address these research gaps by 1.
Specifically examining adherence in children with asthma 2. Using
quality indicators to identify those studies that may be more
informative, and3. Examining the characteristics of adherence
interventions to identify features that may be relevant to practice.