Engblom 1997.

Methods	Study design: parallel RCT Recruitment: men scheduled for elective CABS February 1986‐December 1987 were recruited consecutively Allocation: not reported Blinding: none reported Randomisation: none reported Follow‐up(s): 6 months, 1 year Description: combined rehabilitation programme for CABS patients
Participants	Baseline characteristics Intervention group Mean age (SD): 52 (6) Sex (male %): 100 Number of participants: 66 Working before CHD: 17 Control group Mean age (SD): 51 (6) Sex (male %): 100 Number of participants: 58 Working before CHD: 12 Inclusion criteria Male (RTW is only examined in the subgroup of working men) Elective CABS patients Exclusion criteria > 64 years of age Non‐cardiac diseases prohibitive of participation in the rehabilitation programme Permanently retired patients Baseline imbalances: ‐ Physically demanding work (i.e. white vs. blue collar): white‐collar (42% manual workers) Severity of CHD: severe (LVEF: intervention group: 70%; control group: 71%)
Interventions	Intervention characteristics 4‐phase programme: 2‐day course (2‐3 weeks prior to surgery): information about CABS, recovery, and the rehabilitation programme; group session with a psychologist 3‐week course (6‐8 weeks post‐CABS): standard cardiac rehabilitation programme modified for CABS participants, including lectures and demonstrations on diet and treatment of CAD, exercise and relaxation training, group discussions with a physician and a psychologist 2‐day refresher course (8 months post post‐CABS) 1‐day refresher course (30 months post‐CABS) Duration of intervention: approximately 2.5 years Providers: a group session with a psychologist Control group Usual care
Outcomes	Proportion at work at 6 months–12 months (medium term): 12 months Proportion at work at > 12 months to < 5 years (long term): 3 years Proportion at work at 5 years (extended long term): 5 years Nottingham Health Profile (NHP) Adverse events (death due to cardiac arrest, reinfarction)
Identification	Sponsorship source: none reported. Country: Finland Setting: single centre; outpatient Possible conflicts of interest: none reported Ethics committee approval: not reported
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided to determine risk of bias. The method for generating the random sequence was not described.
Allocation concealment (selection bias)	Unclear risk	No allocation concealment procedure was described. Risk of bias cannot be determined
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	Low risk	None described, but the outcome time until returning to work is not likely to be falsely assessed and cross‐checked with the social registries. Quote: “The employment status of each patient was asked by the physician and later checked from the registries of the Social Insurance Institution of Finland.” (Engblom 1997)
Incomplete outcome data (attrition bias) All outcomes	Low risk	One person in the control "usual care" (H) group died 7 months post‐CABS. In the 5‐year follow‐up, deaths and loss to follow‐up were reported for the entire study population (not just men working at baseline). There appeared to be no notable differences between treatment groups. Quote: “Twelve patients in group R and 13 patients in group H (no significant difference between groups [NS]) died either peri‐ or postoperatively. Two patients in group R and three patients in group H were lost during the follow‐up.”
Selective reporting (reporting bias)	Unclear risk	A study protocol was not available to permit assessment of reporting bias. However, a number of non‐statistically significant results were reported, indicating a reporting bias might not have been a serious problem.
Other bias	Unclear risk	None identified