Heather 2004.

Methods	RCT.
Participants	272 long term (> 6 months) BZD users attending general practice in England. N = 95 patients in intervention group 1; N = 88 patients in intervention group 2; N = 89 patients in control group.
Interventions	Intervention group 1: Consultation group. Patients invited to a consultation with their GP for a medication review. Intervention group 2: Discontinuation letter. Patients received a letter from their GP, advising self‐administered taper. Control group: Usual care.
Outcomes	Change in BZD intake as per prescription of BZDs. A 'true reducer' was somebody who had decreased intake by more than a quarter, including those who had stopped taking completely. Measures were taken at baseline and 6 month follow‐up.
Notes	Review group took the decision to combine consultation group with letter group versus control group. Funding source: Northern and Yorkshire Regional Health Authority R&D Programme (ref: PCC16, January 1997). Declaration of interest: Not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of randomisation not reported.
Allocation concealment (selection bias)	Low risk	"Patients returning an  assessment  questionnaire and consent form were randomly allocated to one of three groups". This was done independently of the doctors carrying out the intervention.
Blinding (performance bias and detection bias) All outcomes	High risk	"Before the trial began, the researcher met participating GPs to give guidance on how the consultation should be carried out". This interaction in one of the three arms of the study could have been a source of bias.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No subjective measures used.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Information relating to BZD intake was prescribing data from charts.
Blinding of outcome assessor (detection bias) subjective outcomes	Unclear risk	No subjective measures used.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing data.
Selective reporting (reporting bias)	Low risk	The study protocol is not available but the published report includes the expected outcome which was pre‐specified in the methods section.