NCT00233181.

Methods	Design: single‐blind, parallel‐group randomised controlled trial Duration: 78 weeks Setting: Paediatric ED in Baltimore. USA Trial registration: NCT00233181
Participants	Population: 250 children with asthma randomised to adherence monitoring and education (n = 83), education (n = 84) or usual care (n = 83) Age: 2 to 12 years of age; mean (SD) age in the adherence group 6.5 (3.43) years, in the education group 7.1 (3.37) years and in the control group 7.4 (3.3) years Baseline asthma severity: not reported Inclusion criteria: eligible for randomisation when between 2 and 12 years of age, physician‐diagnosed asthma, 2 ED visits or 1 hospitalisation for asthma in the preceding year, resided in Baltimore City, prescribed an asthma controller medication Exclusion criteria: not reported Percentage withdrawn: 8.4% from the adherence group, 3.5% from the education group and 8.4% from the control group Other allowed medication: not reported
Interventions	Intervention summary (1): Educational content in the education group PLUS electronic adherence monitoring with feedback, asthma control and adherence goal setting, reinforcement (praise and low‐cost rewards), and strategies for self‐monitoring medication use Intervention summary (2): five 30‐ to 45‐minute home visits by trained asthma educators (AEs) 1, 2, 3, 4 and 8 weeks after randomization. ABC intervention is a home‐based asthma education programme with 5 core components: review of prescribed asthma regimen and training in medication, spacer and peak flow technique; development of an asthma action plan; identification of barriers to accessing healthcare services and problem solving to reduce barriers; discussion of beliefs and concerns about asthma and medications; and provision of written asthma education materials Control summary: asthma education booklet and resource guide that provided information about low‐cost asthma care providers, social services, legal services and other resources. Regardless of group assignment, participants were regularly encouraged to receive care from their primary care provider Complex intervention: yes
Outcomes	Outcomes measured: self‐reported adherence; pharmacy‐based adherence; career reports of symptoms, night‐time awakenings, ED visits, hospitalisations and courses of OCS in the previous 6 months Adherence calculation: Pharmacy‐based adherence was calculated as number of ICS refills per quarter, converted into equivalent values; rates were defined as number of ICS canisters dispensed quarterly (where 3 = 100% adherence). Self‐reported adherence was % use/prescribed dose × 100
Notes	Type of publication: single peer‐reviewed journal article Funding: National Heart, Lung, and Blood Institute grant HL063333
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"To mask staff to group assignment during recruitment, the statistician created block randomization schema and placed the randomization assignments into sealed envelopes, which were opened after families completed baseline surveys"
Allocation concealment (selection bias)	Low risk	"To mask staff to group assignment during recruitment, the statistician created block randomization schema and placed the randomization assignments into sealed envelopes, which were opened after families completed baseline surveys"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were not blinded to group allocation, and knowledge of group allocation and adherence monitoring may have affected healthcare utilisation behaviour, as well as adherence behaviour, beyond the effect intended by trialists
Blinding of outcome assessment (detection bias) All outcomes	High risk	"Trained research assistants who were blinded to study assignments conducted surveys by telephone" However, all asthma morbidity measures were career reported, and therefore were at risk of detection bias, as the career is the outcome assessor for these self‐reported outcomes
Incomplete outcome data (attrition bias) All outcomes	Low risk	More than 80% of participants in all 3 arms completed all questionnaires and follow‐up. Results analysed as ITT, and all randomised participants included in the ITT analysis
Selective reporting (reporting bias)	High risk	Prospectively registered trial (NCT00233181), but not all outcomes (e.g. QOL) reported in the published paper
Other bias	Low risk	None noted