Petrie 2002.

Methods	Study design: parallel RCT Recruitment: consecutive first‐time MI patients admitted to Auckland Hospital over 12‐month period (time period not given) Allocation: not reported Blinding: not reported Randomisation: computer‐generated Follow‐up(s): 3 months Description: individualised education to change illness perception
Participants	Baseline characteristics Intervention Number of participants randomised: 31 Working before CHD: 25 Mean age (SD): 55.3 (8.8) Sex (male %): 74.2 Usual care Number of participants randomised: 34 Working before CHD: 20 Mean age (SD): 55.9 (10.0) Sex (male %): 70.6 Inclusion criteria ≤ 65 years of age at the time of the MI Exclusion criteria: none Baseline imbalances: time in hospital (days): intervention group: 7.7 (4.0); control group: 9.3 (6.2); number working at baseline: intervention group: 80.7%; control group; 58.9% Physically demanding work: unknown Severity of CHD: severe
Interventions	Intervention In‐hospital individualised illness perception counselling Directed counselling Standard MI‐educational material 3x 30‐ to 40‐min sessions conducted by psychologist Session 1: pathophysiology of MI and cardiac vs non‐cardiac symptoms described with illustrations participant’s beliefs and misconceptions about MI were discussed, education regarding other possible causes of MI, i.e. risk factors such as smoking, diet, lack of exercise Session 2: an individualised risk reduction plan and time‐line based on results from Illness Perception Questionnaire assessed at baseline (pre‐randomisation) developed. Plan included exercise, diet and RTW. Session 3: symptoms of recovery discussed warning signs of a further MI, medication use, and participant concerns addressed Duration of intervention: during usual hospital stay Providers: psychologist Control group Usual care In‐hospital visits with cardiac rehabilitation nurse standard MI‐educational material
Outcomes	Proportion at work at < 6 months (short term): 3 months Illness perception questionnaire
Identification	Sponsorship source: Heart Foundation of New Zealand Country: New Zealand Setting: inpatient Possible conflicts of interest: no information provided Ethics committee approval: study authors report obtaining consent and ethics committee approval
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “...patients were randomly assigned into either an intervention or control group using a computer‐generated allocation code.”
Allocation concealment (selection bias)	Unclear risk	No method of allocation concealment was reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Due to the nature of the study, blinding of participants was not possible. However, it is unclear if the participants in the intervention group would have realised they were in the intervention group, since the intervention was integrated into the inpatient hospital care.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No outcome assessor blinding was reported, time until returning to work was assessed with a questionnaire at 3 months. It is unclear if a validated questionnaire item was used to determine the time point of the participants’ RTW
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: “[The 12‐week follow‐up] questionnaire was returned by 56 patients (86%), and non‐respondents did not differ significantly from respondents on any baseline variables.” It is unclear if group assignment (intervention vs control) is considered to be one of the baseline variables.
Selective reporting (reporting bias)	Unclear risk	Unable to determine, no study protocol available
Other bias	Unclear risk	None identified