Table 1 TIDieR description of the intervention (item 2 is shown in Table 2)

Up-front payment

£350 (547 USD, 497 EUR) paid to every practice paid by the research team immediately before practice started the intervention, the same for every practice.

Payment per review

£15 (23 USD, 21 EUR) per review completed, paid by the research team after the end of the 48-week intervention period once the practice submitted an invoice, the same for every practice.

Branding intervention ‘patient safety’

Research team used the term ‘patient safety’ in all communications with all practices.

Prescribing advice

Written by the research team for all practices (not tailored) and communicated and distributed at EOV on a one page laminated sheet.

Structured written educational material reinforcing EOV

Written by the research team for all practices (not tailored) and available electronically from the tool and distributed at the EOV.

Educational outreach visit (EOV)

1 hour face-to-face meeting held in the practice and delivered by the research team to a common basic structure, but tailored according to practice interests and expressed needs (Additional file 1). The EOV summarised the latest research evidence, provided clear prescribing advice, and included training on the tool.

Discussion about potential process to do the work

Discussions facilitated by research team during EOV tailored to specific practice characteristics and wishes.

Newsletters

The research team sent a practice progress report to the lead GP and practice manager 8 weekly both before the practice started the intervention (non-tailored update on the progress of the trial and a reminder of the practice start date) and during the intervention period (tailored to reflect practice progress by providing a run chart, commentary on practice progress including comparison to other practices at the same point in implementing the intervention, and offers of further support) (Additional file 2).

Identification of patients to review

Web-based tool hosted by NHS Tayside, and the same for every practice. Updated weekly using data-extracted from the general practice’s own clinical records. Practice’s had controlled access through personal log in details via the NHS intranet. At log-in, an updated list of patients needing review was available (Additional file 3: Appendix Figures A1 and A3).

Summarise clinical information to facilitate review

The web-based tool provided a structured summary of relevant patient clinical information to facilitate review (summarised risk factors for relevant adverse drug effects, summary of recent relevant prescribing, Additional file 3: Appendix Figure A4).

Run charts of change in prescribing

GPs were required to record their review decisions within the informatics tool in order to receive payment (Additional file 3: Appendix Figures A4 and A5. This information was used to ensure that reviewed patients where prescribing was judged appropriately were not repeatedly flagged for review (to increase efficiency by avoiding pointless re-review) except where prescribing judged inappropriate was restarted (to ensure follow-up of patients where intended care was not delivered).

Timely visual feedback of progress (also used in 8 weekly newsletters in ‘education’) tailored for reach practice and available to view at any time within the informatics tool (Additional file 3: Appendix Figure A2).