Methods	Cluster RCT, with the patient as the unit of randomisation.
Participants	Physicians from 2 emergency departments and two fracture clinics (four hospitals); Patients;Intervention: n=137 and Control: n=135 Country: Canada Type of targeted behaviour: General management of a problem (osteoporosis)
Interventions	Local opinion endorsed guidelines sent to physicians + telephone based patient education (performed by nurses) + reminders sent to physicians Method of OL identification: Sociometric method Proportion of Social Network that nominated OL: UNCLEAR Single OL or OL teams identified: teams of five physicians OL disseminated information: Formal (dissemination of guidelines) OL frequency of involvement: at one time-point sending a signed guideline on osteoporosis care to physician Control: Usual care (provision of printed materials to patients)
Outcomes	Starting biophosphonate treatment within 6 months of the fracture. Bone mineral testing, “appropriate care” (consisting ofbone mineral density testing with treatment ifbone mass was low), and osteoporosis related quality of life
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	p.570/Col 1/Para 3 “In this randomized controlled trial, patients were assigned to either the intervention group or the control group. Allocation was concealed by application of variable block sizes and by use of a secure, centralized, Internet-based, computer-generated randomization system housed within the Epidemiology Coordinating and Research Centre at the University of Alberta in Edmonton.”
Allocation concealment (selection bias)	Low risk	p.570/Col 1/Para 3 “Allocation was concealed by application of variable block sizes and by use of a secure, centralized, Internet-based, computer-generated randomization system ”
Blinding (performance bias and detection bias) All outcomes	Low risk	p.570/Col 1/Para “Patients could not be blinded to the fact that they were part of an osteoporosis quality improvement study. However, physicians were not informed that their patients were part of a study, and neither physicians nor patients were aware of the study outcomes. Research nurses collected outcomes data without knowledge of allocation status. Investigators were blinded at all times.
Incomplete outcome data (attrition bias) All outcomes	Low risk	p.571/Figure 1
Selective reporting (reporting bias)	Low risk	All outcomes mentioned in the methods section were also presented in the results
Other bias	Low risk
Similar baseline outcome measures?	Low risk	p.572/Table 1
Similar baseline characteristics?	High risk	p.572/Table 1
Protection against contamination?	Low risk	The study was a cluster RCT.