Bengtsson 1983.

Methods	Study design: parallel RCT Recruitment: October 1973‐January 1975 Allocation: no information provided Blinding: not reported Randomisation: “…allocated at random"; no further information provided Follow‐up(s): 8‐19 months (average 14 months) Description: combined rehabilitation programme with recommendations for work modifications
Participants	Baseline characteristics Intervention group Mean age (SD): 55.3 (6.6) Sex (male %): 86 Number of participants randomised: 44 Working before CHD (number self‐calculated): 36 Control group Mean age (SD): 57.1 (6.6) Sex (male %): 84 Number of participants randomised: 43 Working before CHD (number self‐calculated): 40 Inclusion criteria < 65 years of age MI patients Exclusion criteria Severe heart failure, post‐MI syndrome, aortic regurgitation, cerebral infarct, hemiparesis Diseases of the hip, post‐poliomyelitis, amputation of a lower extremity Diabetes mellitus with retinopathy, hyperthyroidism, hypothyroidism, hyperparathyroidism Mental illness: anxiety neurosis, low intelligence, alcoholism, schizophrenia Living > 50 km from the hospital Baseline imbalances: ‐ Physically demanding work (i.e. white‐ vs blue‐collar): unknown Severity of CHD: severe (severe cardiac failure excluded, angina not excluded)
Interventions	Intervention characteristics Rehabilitation programme Outpatient examination: detailed health, work and family history attitudes toward illness exercise tolerance test on ergometer Physical training supervised by physiotherapist for 30 min 2 x/week over 3 months: interval training of large muscle groups on mechanically braked ergometer bicycle (Monark Ergometercykel) callisthenics 30 min jogging (2 x/week over 3 months) intensity was graded on basis of exercise tolerance test findings; maximum heart rate = 90% of maximum heart rate at exercise Counselling, individually and in groups (topics included avoiding weight gain, smoking cessation, continued physical exercise, resuming leisure activities, social benefits, and return‐to‐work) Classes regarding causes of MI (anatomy of the heart, psychological reactions, mode of life), course, treatment (drug treatment) Counselling of family members Social measures: medical reports sent to insurance, employer, local employment authority, disablement resettlement officer recommendations for work modifications issued to employer (in 4 cases) report (course of illness, performance on exercise tolerance test, drug therapy, plans for maintenance treatment) was sent to participants’ doctors Duration of intervention: about 3.5 months (from 1.5–5 months post‐MI) Providers: physiotherapists, cardiologist (qualifications for counselling provider not described) Control group Usual care (not explicitly stated)
Outcomes	Proportion at work at > 12 months to < 5 years (long term): about 13.5 months Working status ascertained at follow‐up examination between 8 and 19 months Mean sick leave (days) Minnesotal Multiphasic Personality Inventory Adverse events (mortality, reinfarction)
Identification	Sponsorship source: none reported Country: Sweden Setting: single‐centre; outpatient Possible conflicts of interest: no information provided Ethics committee approval: no information provided regarding patient consent or ethics committee approval
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“…allocated at random to either the rehabilitation (81) or the control (90) group…” No further information provided
Allocation concealment (selection bias)	Unclear risk	No information regarding allocation concealment was reported.
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	Neither blinding of outcome assessors, nor how work status was assessed was reported.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The study authors attempted an intention‐to‐treat analysis. Quote: “Seven who were invited to take part [in the treatment programme] declined; 6 of these were seen at follow‐up examination, and were included in the rehabilitation group because the control group probably also comprised a comparable number of patients who would no doubt also have declined further treatment.” However the impact of adverse effects was not assessed. Quote: “Those patients who developed a new infarction during the investigation period were excluded, because the follow‐up interview was focused on experiences of MI at time of entry to the study.”
Selective reporting (reporting bias)	Unclear risk	Unable to determine, no study protocol available
Other bias	Unclear risk	None identified