Methods	Parallel group RCT, UK
Participants	87 patients randomised. All patients post-MI. Mean age 63 years. 87% male
Interventions	INTERVENTION: Letters based on the theory of planned behaviour (Ajzen and Madden, 1986107) designed to increase attendance at outpatient CR were given to patients 3 days post-MI and sent 3 weeks post-MI. The first letter was designed to influence acceptance and the second was designed to influence attendance. Patients also received a nominal letter of thanks at three days and the standard letter detailing course dates as sent to control patients. After allocation to groups the CR nurse saw all patients for routine assessment and personal invitation to the programme. For patients who declined the offer of a place a brief second letter was sent wishing them well and informing them that they were still welcome to contact the team COMPARISON: Nominal letter of thanks given to patients at three days post-MI and the standard letter detailing course dates
Outcomes	Uptake (defined as attendance at the outpatient CR programme)
Notes	Women were less likely to attend the programme, but neither age nor distance lived from the programme predicted attendance. Authors note that the intervention may have worked by acting as a fear message, rather than through implementation of theory of planned behaviour
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	Allocation by random number assignment
Allocation concealment?	Yes	Patients were handed a sealed numbered envelope with a nominal letter. Half of the envelopes also contained an intervention letter. Envelope contents known to a research assistant only
Free of other bias?	No	CR nurse not aware of group assigned to; however, no procedure in place to stop patients telling nurse which letter received
Blind outcome assessment? All outcomes	Unclear	Uptake defined as saying yes to cardiac nurse. Participants may have mentioned the letter received