WHO 1983.

Methods	Study design: multi‐centre, RCT Recruitment: 24 centres; hospitalised AMI patients from June 1973‐October 1975 Allocation: not reported Blinding: not reported Randomisation: random numbers table (some centres applied cluster‐randomisation or a non‐randomised control group) Follow‐up(s): 3, 6, 12 months, 2 and 3 years Description: combined rehabilitation programme
Participants	Baseline characteristics Intervention group (rehabilitation) Age (%): 38% < 50 years; 41% 50‐59 years; 21% 60‐65 years Sex (male %): 100 Number of participants randomised: 1655 Working before CHD: ‐ Control group Mean age (SD): 34% < 50 years; 39% 50‐59 years; 28% 60‐65 years Sex (male %): 100 Number of participants randomised: 1529 Working before CHD: ‐ Inclusion criteria Diagnosed with AMI and treated in hospital Male Aged < 66 at AMI Exclusion criteria ‐ Baseline imbalances: ‐ Physically demanding work: unknown Severity of CHD: severe
Interventions	Intervention characteristics Each centre developed their own combined rehabilitation programme. The programmes' goals were to improve health by addressing the following. Treatment of underlying conditions and relevant co‐morbidities (e.g. heart failure, diabetes, etc.) Risk factors (e.g. weight and serum lipid level reduction, smoking cessation, reduction of alcohol consumption, etc) Increase physical working capacity "Psychological, social and vocational sequelae of AMI had to be identified and corrected as far as possible" Physical training (optional) Duration of intervention: ‐ Providers: ‐ Control group Usual care according to the region of the centre
Outcomes	Proportion at work at < 6 months (short term): 3 months Proportion at work at 6–12 months (medium term): 12 months Proportion at work at > 12 months to < 5 years (long term): 3 years Adverse events (mortality, reinfarctions, non‐fatal reinfarctions)
Identification	Sponsorship source: WHO Country: international Setting: ‐ Possible conflicts of interest: no information provided Ethics committee approval: not reported
Notes	The results of the individual centres were often published separately and the number of people included in the RTW results were not reported, therefore this study is not included in the meta‐analyses.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Although the study protocol called for the randomisation of participants according to random number tables, some study centres applied cluster‐randomisation or a selected a non‐randomised control group (i.e. control hospital). Also the study authors write, "Only 12 centres out of the 24 seemed to have achieved proper randomisation in their groups of R and C patients".
Allocation concealment (selection bias)	Unclear risk	None described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Due to the nature of the study, blinding of participants was not possible.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	None described
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "By 1 April 1970 data on follow‐up over a three‐year period were available for about 78% of all patients initially enrolled in the study." Overall 22% loss to follow‐up
Selective reporting (reporting bias)	Low risk	All of the results' proposed analyses seem to have been reported.
Other bias	Unclear risk	None identified