BACKGROUND

Asthma is a common respiratory condition in children that is characterised by symptoms including wheeze, shortness of breath, chest tightness, and cough. Children with asthma may be able to manage their condition more effectively by improving inhaler technique, and by recognising and responding to symptoms. Schools offer a potentially supportive environment for delivering interventions aimed at improving self-management skills among children. The educational ethos aligns with skill and knowledge acquisition and makes it easier to reach children with asthma who do not regularly engage with primary care. Given the multi-faceted nature of self-management interventions, there is a need to understand the combination of intervention features that are associated with successful delivery of asthma self-management programmes.

OBJECTIVES

This review has two primary objectives.• To identify the intervention features that are aligned with successful intervention implementation.• To assess effectiveness of school-based interventions provided to improve asthma self-management among children.We addressed the first objective by performing qualitative comparative analysis (QCA), a synthesis method described in depth later, of process evaluation studies to identify the combination of intervention components and processes that are aligned with successful intervention implementation.We pursued the second objective by undertaking meta-analyses of outcomes reported by outcome evaluation studies. We explored the link between how well an intervention is implemented and its effectiveness by using separate models, as well as by undertaking additional subgroup analyses.

SEARCH METHODS

We searched the Cochrane Airways Trials Register for randomised studies. To identify eligible process evaluation studies, we searched MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, the Cochrane Database of Systematic Reviews (CDSR), Web of Knowledge, the Database of Promoting Health Effectiveness Reviews (DoPHER), the Database of Abstracts of Reviews of Effects (DARE), the International Biography of Social Science (IBSS), Bibliomap, Health Technology Assessment (HTA), Applied Social Sciences Index and Abstracts (ASSIA), and Sociological Abstracts (SocAbs). We conducted the latest search on 28 August 2017.

SELECTION CRITERIA

Participants were school-aged children with asthma who received the intervention in school. Interventions were eligible if their purpose was to help children improve management of their asthma by increasing knowledge, enhancing skills, or changing behaviour. Studies relevant to our first objective could be based on an experimental or quasi-experimental design and could use qualitative or quantitative methods of data collection. For the second objective we included randomised controlled trials (RCTs) where children were allocated individually or in clusters (e.g. classrooms or schools) to self-management interventions or no intervention control.

DATA COLLECTION AND ANALYSIS

We used qualitative comparative analysis (QCA) to identify intervention features that lead to successful implementation of asthma self-management interventions. We measured implementation success by reviewing reports of attrition, intervention dosage, and treatment adherence, irrespective of effects of the interventions.To measure the effects of interventions, we combined data from eligible studies for our primary outcomes: admission to hospital, emergency department (ED) visits, absence from school, and days of restricted activity due to asthma symptoms. Secondary outcomes included unplanned visits to healthcare providers, daytime and night-time symptoms, use of reliever therapies, and health-related quality of life as measured by the Asthma Quality of Life Questionnaire (AQLQ).

MAIN RESULTS

We included 55 studies in the review. Thirty-three studies in 14,174 children provided information for the QCA, and 33 RCTs in 12,623 children measured the effects of interventions. Eleven studies contributed to both the QCA and the analysis of effectiveness. Most studies were conducted in North America in socially disadvantaged populations. High school students were better represented among studies contributing to the QCA than in studies contributing to effectiveness evaluations, which more commonly included younger elementary and junior high school students. The interventions all attempted to improve knowledge of asthma, its triggers, and stressed the importance of regular practitioner review, although there was variation in how they were delivered.QCA results highlighted the importance of an intervention being theory driven, along with the importance of factors such as parent involvement, child satisfaction, and running the intervention outside the child's own time as drivers of successful implementation.Compared with no intervention, school-based self-management interventions probably reduce mean hospitalisations by an average of about 0.16 admissions per child over 12 months (SMD -0.19, 95% CI -0.35 to -0.04; 1873 participants; 6 studies, moderate certainty evidence). They may reduce the number of children who visit EDs from 7.5% to 5.4% over 12 months (OR 0.70, 95% CI 0.53 to 0.92; 3883 participants; 13 studies, low certainty evidence), and probably reduce unplanned visits to hospitals or primary care from 26% to 21% at 6 to 9 months (OR 0.74, 95% CI 0.60 to 0.90; 3490 participants; 5 studies, moderate certainty evidence). Self-management interventions probably reduce the number of days of restricted activity by just under half a day over a two-week period (MD 0.38 days 95% CI -0.41 to -0.18; 1852 participants; 3 studies, moderate certainty evidence). Effects of interventions on school absence are uncertain due to the variation between the results of the studies (MD 0.4 fewer school days missed per year with self-management (-1.25 to 0.45; 4609 participants; 10 studies, low certainty evidence). Evidence is insufficient to show whether the requirement for reliever medications is affected by these interventions (OR 0.52, 95% CI 0.15 to 1.81; 437 participants; 2 studies; very low-certainty evidence). Self-management interventions probably improve children's asthma-related quality of life by a small amount (MD 0.36 units higher on the Paediatric AQLQ(95% CI 0.06 to 0.64; 2587 participants; 7 studies, moderate certainty evidence).

AUTHORS' CONCLUSIONS: School-based asthma self-management interventions probably reduce hospital admission and may slightly reduce ED attendance, although their impact on school attendance could not be measured reliably. They may also reduce the number of days where children experience asthma symptoms, and probably lead to small improvements in asthma-related quality of life. Many of the studies tested the intervention in younger children from socially disadvantaged populations. Interventions that had a theoretical framework, engaged parents and were run outside of children's free time were associated with successful implementation.