Heller 1993.

Methods	Study design: Cluster randomised multicentre RCT Country: Australia Dates patients recruited: 18 September 1990 to 5 December 1991 Maximum follow up: 6 months
Participants	Inclusion criteria: < 70 years with a suspected heart attack registered by the Newcastle collaborating centre of the WHO MONICA Project and discharged alive from hospital. Exclusion criteria: Renal failure or other special dietary requirements and those considered by their physicians to have 'endstage' heart disease. N Randomised: total: 450; intervention: 213; comparator: 237 Diagnosis (% of pts): MI: 100% Age (mean ± SD): intervention: 59 ± 8; comparator: 58 ± 8 Percentage male: 71% Ethnicity: NR
Interventions	Intervention: A mail‐out programme designed to help patients reduce dietary fat, obtain regular exercise by walking and to quit smoking. 1st package: Step 1 "Facts on fat" kit, together with walking programmme information, encouragement to walk in the form of a magnetic reminder sticker, and "Quit for Life" programme for smokers. 2nd package: Steps 2‐3 "Facts on fat" kit; exercise log. 3rd package: Steps 4‐5 "Facts on fat" kit, together with information regarding local "Walking for Pleasure" groups. Components: exercise plus education. Setting: home. Aerobic exercise: Modality: walking. Length of session: NR Frequency: NR Intensity: NR Resistance training included? NR Total duration: 6 months. Co‐interventions: Supplementary telephone contact was also used and a letter was sent to the family doctor regarding the benefit of aspirin and β blockers for secondary prevention. Comparator: usual care. Co‐interventions: none described.
Outcomes	Total mortality, HRQL. Study outcomes assessed at 6 months.
Source of funding	National Health and Medical Research Council of Australia.
Conflicts of interest	NR
Notes	Low use of preventative services (dietary, anti smoking) by both groups. 10% of patients received CR ‐ mostly having had CABG.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Cluster randomisation by GP. "All general practices were randomly allocated to intervention or usual care within those strata." Method of randomisation not described.
Allocation concealment (selection bias)	Unclear risk	Not reported.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	17% lost to follow up, no description of withdrawals or dropouts.
Selective reporting (reporting bias)	Low risk	All outcomes reported at all time points.
Groups balanced at baseline	Low risk	There were no significant differences in demographic characteristics, medical history or patterns of consumption of tobacco, alcohol and fat.
Intention‐to‐treat analysis conducted	Low risk	Yes.
Groups received same treatment (apart from the intervention)	High risk	“A low‐cost mail‐out program was designed to help patients reduce dietary fat, obtain regular exercise by walking and (for smokers only) to quit smoking. Supplementary telephone contact was also used.”