Landon 2007.

Methods	CBA, patient recruitment: patients/clients of primary care clinic or pharmacy Setting: Community health centres throughout USA (n = 48)
Participants	Control patients: n = not clear, women: 67.6%, mean age: 34.4, asthma severity: not reported, FEV1: not reported, ICS use: not reported Intervention patients: n = not clear, women: 63.5%, mean age: 28.4, asthma severity: not reported, FEV1: not reported, ICS use: not reported Total patients with asthma: n = 3392
Interventions	Name and duration of programme: Health Disparities Collaboratives (each generally including 20 or more community health centres) disseminating quality improvement techniques developed by the Institute for Healthcare Improvement, during 4.5 years Intervention group components* Organisational ‐ patients: community linkages component (access to resources (e.g., donated medical services) in the community for the benefit of patients in community health centres; providing services to an entire community (e.g., “Diabetes Awareness Day”)) Organisational ‐ healthcare professionals or system: delivery system redesign components (improvement of care management, missed‐appointment follow‐up, organisation of the practice team; change of care delivery roles; patient visits planning); decision support component (guidelines, protocols, and prompts; providers education; facilitating specialty and expert consultation); information support components (patient registry systems; improving the collection or use of data for care management; providing performance data to individual providers or to the group or organisation); health system organisation component (increase administrators' motivation and ability to improve care for patients with chronic disease, increase providers’ motivation and ability to be involved in such improvements, or improve the overall ability of the system or institution to engage in co‐ordinated quality improvement efforts); physician training; explicit teamwork (creation of improvement teams) Patient education and self‐management support: self‐care support component (providing education or care guidelines to patients, increase patient motivation for self‐care, assessment of self‐care needs or abilities, providing support tools or resources to improve self‐care, collaborative decision making with patients) Frequency: variable in the centres Healthcare professionals involved: teams from community health centres Control group components Usual care Number of components and dominant component: ≥11, organisational ‐ healthcare professionals or system
Outcomes	Organisational level Process outcomes: % patients with an action plan; % patients assessed for smoking status and cessation advice; % patients assessed for exposure to smoke; % patients with advice on smoking; % patients vaccinated for influenza; % patients assessed for asthma severity; overall quality of care provided score (prevention and screening, monitoring and treatment, outcomes) Healthcare utilisation: % patients with no urgent care, ER visit, hospitalisation for asthma Patient level Asthma symptoms and activity level: % patients treated with anti‐inflammatory medication Time of outcome measurement: at 2 to 3 years
Notes	*The study evaluated a range of interventions that took place in 48 community health centres. Each intervention had to include at least 1 component of the 6 major components described above
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No randomisation
Allocation concealment (selection bias)	High risk	No randomisation
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Unclear whether outcome assessment was blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear whether all data were collected
Selective reporting (reporting bias)	Unclear risk	No protocol
Other bias	Unclear risk	No other bias detected
Outcomes at baseline similar?	Unclear risk	No P values provided for comparisons between groups
Characteristics at baseline similar?	Unclear risk	Significant differences between groups for Charlson morbidity index, age and insurance type
Adequate protection against contamination?	Low risk	External control centres