Majumdar 2007.

Methods	Study design: Cluster‐randomised trial, with the healthcare professional as the unit of randomisation Sample size calculation: with a 20% intervention‐related increase in the primary outcome as the effect size, setting ą error at .05 (2‐sided) and β error at .20, a minimal sample size of 140 was estimated. To allow for losses, one secondary analysis, and the possibility of a small design effect associated with statistical clustering, we adjusted the sample size to 160 patients.
Participants	Providers: 769 primary care physicians were randomised but only 128 physicians contributed any patients. Participants (patients): 171 patients with heart failure (HF) and Ischaemic heart disease (IHD): Intervention: N = 87 (29 HF and 58 IHD); Control: N = 84 (26 HF and 59 IHD) Setting: one large health system Country: Canada Type of targeted behaviour: general management of a clinical problem (improved prescribing for HF and IHD)
Interventions	Description of the intervention: one page evidence summaries generated and endorsed by OLs Method of OL identification: sociometric Proportion of social network that nominated OL: 30% of 788 physicians who were faxed a one‐page sociometric questionnaire that asked them to nominate physicians who best matched validated descriptions of OLs. OLs (single or teams): teams of five physicians (3 cardiologists, 2 general internists, none was a university based academic cardiologist) OL disseminated information: formal (faxed evidence summaries) OL frequency of involvement: one action taken at one time point (most physicians received only one faxed evidence summary) Control: standard care (the patients most recent medication profile was faxed to the physician) Duration of intervention: 6 months Funding: "This study was supported by grants from the AHFMR (Alberta Heritage Foundation for Medical Research; Edmonton, Alberta, Canada) and the Institute of Health Economics. Drs Majumdar and McAlister received salary awards from the AHFMR and the Canadian Institutes of Health Research (Ottawa, Ontario, Canada). Drs McAlister and Tsuyuki are supported by the Merck Frosst/Aventis Chair in Patient Health Management."
Outcomes	Primary outcomes: Use of efficacious therapies (ACE inhibitors or ARBs in HF and statins in IHD)* Secondary outcomes: Prescribing changes for HF and IHD Follow‐up: 6 months after enrolment
Notes	* Sample size calculation was based on this outcome.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	pg 22.e2/col 2/para 5 "Simple randomisation with concealment of allocation was performed at the level of the physician before patient recruitment started with the use of a computer‐generated sequence."
Allocation concealment (selection bias)	Low risk	pg 22.e2/col 2/para 5 "Simple randomisation with concealment of allocation was performed at the level of the physician before patient recruitment started with the use of a computer‐generated sequence." "Each physician was randomly allocated to the HF intervention or to HF control; physicians allocated to the HF intervention were automatically assigned to IHD control and vice versa."
Baseline outcome measurements similar	Low risk	pg 22.e4/col 1/para 2 "The intervention patients and control subjects were comparable, with no important differences between them (Table I)." None of the participants had previously been prescribed any of the study medications.
Baseline characteristics similar	Low risk	pg 22.e4/col 1/para 2 The intervention patients and control subjects were comparable, with no important differences between them (Table I).
Blinding (performance bias and detection bias) All outcomes	Low risk	pg 22.e2/col 1/para 3 "All outcomes were ascertained in an independent and blinded fashion, and allocation was concealed from patients, investigators, data collectors, and analysts."
Incomplete outcome data (attrition bias) All outcomes	Low risk	No study patient was lost to follow‐up.
Protection against contamination	Low risk	Cluster‐randomised trial protected against contamination.
Selective reporting (reporting bias)	Low risk	All outcomes mentioned in the methods section were presented in the results.
Other bias	Low risk	No other risk of bias identified