Methods
Search Strategy
PubMed, Embase, PsychINFO, Medline, Web of Science, and International
Pharmaceutical Abstracts databases were searched systematically from the
date of database inception until 3rd October 2020 to
identify relevant literature. MeSH, Emtree and truncated terms were used
where applicable (E-table 1). Key search terms were: asthma, child,
Intervention, adherence and randomized. All authors were contacted via
email or, if not reachable via this route, by ResearchGate messaging for
further details about the studies.
Study selection
Authors CP and TJ reviewed the abstracts, followed by the full texts
against the inclusion/exclusion criteria. Where there were differing
opinions a third, opinion was sought (RH). Inclusion criteria were based
on the Participant-Intervention-Comparison-Outcome-Study Design (PICOS)
framework. Any interventions that focused on adherence to ICS with at
least one outcome measure of adherence and used a randomised control
trial (RCT) design were included. The comparison group was either usual
treatment or basic education arms. Articles were included where the full
text was written in English, and where the population of interest was
patients aged 0-18 years old with a diagnosis of asthma. Although many
preschool children with wheeze do not respond to ICS16, studies often recruit younger children and
therefore this age-range was intended to avoid missing relevant
articles. If they do not have the treatable trait of airway eosinophilia
likely to respond to ICS 17 this will be highlighted
in the section regarding reliability of the criteria for asthma
diagnosis. Studies were excluded if they did not meet the above criteria
or if they were an RCT comparing two medications only, or where the
majority of participants were not children (e.g. the mean age of
participants was over 18 years or only adults were recruited).
Data Extraction and
Synthesis
Following full-text review, CP and TJ extracted details of: study
characteristics (setting, number of participants, diagnosis criteria,
intervention and control descriptions and the outcome of interest);
Effectiveness; Risk of Bias (RoB); and Behaviour change techniques
(BCTs); target of the BCTs; relationship to PAPA.
Intervention Content
Intervention content were coded for PAPA as follows: Level 1
(intervention only targeted perceptions or only practicalities and not
tailored); Level 2 (both perceptions and practicalities targeted but not
tailored or only targeting one component (perceptions or practicalities)
and tailored) and Level 3 (both perceptions and practicalities targeted
and tailored to the individual).
Specific components within the intervention for changing adherence
(Behaviour Change Techniques; BCTs) were also coded independently using
BCT taxonomy V1 app 18. Any differences in the
selected BCTs were discussed until consensus was reached (Table 1).
Risk of Bias
RoB was assessed independently using the Cochrane Risk of Bias Handbook19 by CP, AC and HF using the Covidence platform
(www.covidence.org) to record
coding decisions and consensus discussions. The RoB score was based on
the adherence outcome. Each study was scored across five domains:
selection bias; performance and detection bias, attrition bias and
reporting bias, and was scored as either low, high or unclear risk for
each study. Authors were contacted for clarity when information relating
to domains seemed unclear.
Study Reliability
To ascertain which interventions were truly effective, study reliability
was considered. Although other validated tools have been used to assess
quality such as the Grading of Recommendations, Assessment, Development
and Evaluations (GRADE) tool 20 the authors felt that
there were several crossovers between risk of bias, the reliability
scores, the 3CBC approach and in particular, the indirectness section of
the GRADE tool and based on the aim of this review the reliability
measurements would be more useful when considered with RoB. Both
diagnosis and adherence measures can range from being subjective to
objective, therefore considering the reliability of the approaches used
is key for determining study reliability. Through multidisciplinary team
discussions (including with respiratory physicians, pharmacists and a
health psychologist) a coding hierarchy that considered the reliability
of the asthma diagnosis and adherence measurement used was created and
applied to the specific studies within this review (E-table 2).
Based on the RoB, the reliability of the asthma diagnosis, and the
objectivity of the adherence measurement, the most reliable and least
biased studies were used to ascertain what components constituted an
effective intervention. Previous literature suggests that optimising the
context, channel of delivery, and content of the intervention is
important for intervention effectiveness 11, and thus
the 3CBC 11 was also applied to this review.
Studies were summarised by a narrative synthesis. Meta-analysis was not
conducted due to the wide study heterogeneity in terms of setting,
asthma diagnosis criteria, and outcome measures used. The study protocol
is published on PROSPERO
(https://www.crd.york.ac.uk/prospero/#searchadvanced)
(ref: CRD42016029213).