Clark 2004.

Methods	Included as outcome evaluation Study design: clustered parallel‐group design with schools selected as the unit of randomisation Setting: study was conducted at 14 public high schools in Detroit, Michigan, USA. Seven schools (416 children) were assigned to the treatment arm, and 7 schools (419 children) to the control group Period: dates on which study was conducted ‐ intervention and subsequent data collection ‐ were not clear; follow‐up data were collected 2 years after baseline
Participants	Eligible sample frame: following a case detection survey, 1217 children were identified as eligible and 835 parents provided consent for their child to participate Randomised: 835 pupils randomised at the school level: 416 to the treatment group and 419 to the control group Completed (intervention): unclear; 674 parents participated in follow‐up survey 2 years later, but this was not disaggregated and completion figures were not provided Inclusion criteria: students were eligible for participation in the study if they had: "(1) a physician’s diagnosis of asthma and active symptoms, or a diagnosis and received a prescription for asthma medications in the previous year; or (2) no physician’s diagnosis, but reported presence of three or more of seven asthma symptoms in the past year, or reported either of two exercise‐related asthma symptoms with frequency of three times or more, in the past year" Exclusion criteria: no additional exclusion criteria reported Baseline characteristics Age of children: all children were in grades 2 through 5; 93% were between 7 years and 10 years of age Ethnicity: 98% of children were African American Socio‐economic status: schools were located in areas of high poverty. Almost half of students (45%) were from families with annual income under $15,000 Gender: no gender breakdown was provided Asthma status: 236 students had mild persistent asthma (28.3%), 128 had moderate asthma (15.3%), and 40 had severe asthma (4.7%)
Interventions	Intervention This was a comprehensive programme of asthma self‐management targeted at children, caregivers, and the wider school: "The program elements were as follows: (1) OAS disease management training for children adapted to local needs (for example, related to smoking among elementary school‐aged children), which included handouts and homework assignments involving parents; (2) 'Environmental Detective', two classroom sessions for classmates to enhance their understanding of factors that may influence respiratory health in general, and to help them develop empathy for children with asthma in particular; (3) orientation to asthma and control strategies for school principals and counsellors; (4) briefings and building walk‐throughs for custodial personnel regarding potential environmental triggers to asthma symptoms and practical means of remediation; (5) school fairs for children and their caretakers, including asthma care question‐and‐answer sessions for the adults; (6) written communication on behalf of the family with the child’s clinician providing information about the school program, encouraging completion of an asthma action plan for the child, and requesting provision of a copy to the school" Control: wait‐list control (usual care) Intensity: target students received OAS training (which usually consists of 6*60‐minute sessions) as well as 2 additional classroom sessions through the 'environmental detective' component Instructor: not reported Theoretical framework: not explicitly described Parental engagement: not reported in detail, although elements of the programme reported as having been "completed with reasonable success", except the element that involved written communication with the child's physician Child satisfaction: not reported Timing of intervention in school day: not reported
Outcomes	Selected outcomes were extracted but were not combined in meta‐analyses due to incompatibility of unit of analysis (risk difference) between this study and others
Notes	Absence from school and experience of daytime and night‐time symptoms were collected in the study, but sample sizes disaggregated by study arm that could allow for extraction and inclusion in meta‐analysis were not included Funding source: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Schools were randomly assigned via a random numbers table to receive the programme (7 schools and 416 children) or to be assigned to a wait‐list control group (7 schools and 419 children)
Allocation concealment (selection bias)	High risk	Use of pre‐defined random number table potentially compromised allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No information was provided on blinding; this was not addressed by study authors
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information was provided on blinding; this was not addressed by study authors
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear ‐ full information on attrition was not presented
Selective reporting (reporting bias)	Low risk	No evidence indicated selective reporting (although the unit of analysis was incompatible for the meta‐analytical framework implemented)
Other bias	Low risk	Missingness ‐ unclear ‐ information on missing data was not provided Baseline imbalance ‐ low risk ‐ no differences in characteristics of intervention and control groups were described Risk of contamination ‐ low ‐ schools were the unit of randomisation, providing low risk of contamination
Transparent and clearly stated aims	Unclear risk	N/A
Explicit theories underpinning and/or literature review	Unclear risk	N/A
Transparent and clearly stated methods and tools	Unclear risk	N/A
Selective reporting	Unclear risk	N/A
Harmful effects	Unclear risk	N/A
Population and sample described well	Unclear risk	N/A
Continuous evaluation	Unclear risk	N/A
Evaluation participation equity and sampling	Unclear risk	N/A
Design and methods overall approach	Unclear risk	N/A
Tools and methods of data collection reliable/credible	Unclear risk	N/A
Tools and methods of data analysis reliable/credible	Unclear risk	N/A
Performance bias/neutrality/credibility/conformability	Unclear risk	N/A
Reliability of findings and recommendations	Unclear risk	N/A
Transferability of findings	Unclear risk	N/A
Overall risk of bias of process evaluation	Unclear risk	N/A