Polek 2012.

Methods	Nested randomised controlled trial
Participants	N randomised: intervention = 25 versus usual care = 28 Diagnosis of patients: mixed indication cohort Demographics of the cohort: Age: mean 63.71 (SD 16.04) % female: not stated % white: not stated % education above primary level: not stated Demographics of the AF patients: N = 14 Treatment group n = 5; usual care n = 9 Age: mean intervention = 73.6 (SD 11.1) versus mean usual care = 76 (SD 13.4) % female: intervention = 4/5 (80%) versus usual care = 3/9 (33%) % white: intervention = 3/5 (60%) versus usual care = 5/9 (55%) % educated above primary school level: not available Inclusion criteria: patients discharged to home on OAT, alert and orientated, able to speak and understand English, and accessible via telephone Exclusion criteria: patients discharged to a nursing home or rehabilitation facility, history of psychotic disorder or cognitive impairment
Interventions	Type: enhanced educational intervention Content: face‐to‐face warfarin education, printed materials, instruction, medical alert bracelet. The intervention was based on Banduras social cognitive model and aimed to improve self‐efficacy. Four post‐discharge phone calls assessing knowledge post‐intervention and correcting incorrect answers. Duration: not stated Facilitator: pharmacist Setting: hospital
Outcomes	warfarin knowledge self‐efficacy
Country	USA
Comparison	usual care
Length follow‐up	12 weeks
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Patients were randomly assigned to the intervention or usual care group after receiving patient education from the pharmacist. Authors do not describe the sequence generation.
Allocation concealment (selection bias)	Unclear risk	Of 66 patients who were screened and offered participation in the study, there were 53 included in the original randomised sample (80% of those screened), with a low risk of inclusion bias. Only 42/53 (79%) received the intervention or usual care; 42/66 of eligible patients were therefore included (64%).
Blinding of participants and personnel (performance bias) All outcomes	High risk	The authors do not state whether the researchers or personnel were blinded regarding to which arm the participants were randomised. However, we can assume that participants and physicians were not blinded to treatment allocation due to the nature of the intervention. The authors do not state whether the personnel delivering the intervention also treated the usual care arm.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Authors do not state whether the person scoring the questionnaires was blinded to the treatment allocation.
Incomplete outcome data (attrition bias) All outcomes	High risk	The final sample included 42 (79%) of the original 53 patients that were randomised to the study. Attrition was 36% and therefore designated as high risk of bias.
Selective reporting (reporting bias)	Low risk	The authors describe two outcomes in their method section: (1) warfarin knowledge and (2) self‐efficacy. The authors report on both outcomes in their results section. There was no published protocol paper, thus we cannot determine whether those outcomes reported reflect those that were included in the study.
Other bias	High risk	Very small sample size (N = 42 in total)