Picard 1989.

Methods	Study design: parallel RCT Recruitment: recruited at Kaiser Foundation Hospitals in Redwood City, Santa Clara, San Jose, Hayward and South San Francisco, USA. July 1983‐ September 1985 Allocation: sealed envelopes Blinding: not reported Randomisation: sealed envelopes with an equal number of group assignments were shuffled into random order and each new patient was assigned with the top envelope on the stack Follow‐up(s): 6 months Description: intervention provided AMI patients eligible for treadmill testing with a RTW consultation including a recommendation for RTW based on results of treadmill testing
Participants	Baseline characteristics Intervention group Mean age (SD): 50 (7) Sex (male %): 100 Number of participants randomised: 99 Working before CHD: 99 Usual Care Group Mean age (SD): 49 (7) Sex (male %): 100 Number of participants randomised: 102 Working before CHD: 102 Inclusion criteria Men < 60 years of age AMI In full‐time employment (≥ 36 hours/week) for at least 3 months prior to AMI Low‐risk participants eligible for treadmill testing based on the DeBusk 1983 risk stratification model (e.g. absence of cardiac failure and [unstable] angina at rest on the 5th hospital day) Exclusion criteria Cardiac failure (on 5th hospital day) Angina at rest (on 5th hospital day) Baseline imbalances: ‐ Physically demanding work: white‐collar Severity of CHD: severe (patients with ventricular fibrillation included; intervention group n = 8; control group n = 3)
Interventions	Intervention characteristics Occupational work evaluation treadmill testing approximately 21 days post‐AMI: cardiac medications tapered off at least 3 half‐lives prior to treadmill testing cardiovascular history and physical examination symptom‐limited treadmill‐testing (Naughton protocol): started at 3 Metabolic Equivalents (METs) (est. multiples of resting oxygen consumption) and increased by 1 MET/3 min until symptoms of fatigue, dyspnoea, moderate angina, dizziness, leg cramps, signs of exertional hypotension (decrease in systolic BP > 10 mmHg vs previous stage), ventricular tachycardia, staggering gait, blank facies cuff BP and 12‐lead ECG at rest and at the end of each stage of exercise and every min during 10‐min recovery ischaemic treadmill response defined as development of angina or ≥ 0.1mV of ST depression at 0.8 second after the J point in any lead during exercise or recovery RTW recommendations based on treadmill results, and an algorithm estimating the 1‐year risk of recurrent infarction/cardiac death: 5% risk advised to RTW at 35 days 10% risk advised to return to work at 42 days after beginning antianginal medication 25% risk advised to undergo coronary arteriography before returning to work (performed within 3 weeks and referred to primary physician) Duration of intervention: 1 outpatient visit at ca. 21 days post AMI Providers: cardiologist nurse clinician Control group Usual care at the Kaiser Foundation Hospitals
Outcomes	Proportion at work (part‐/full‐time) at 6 months–12 months (medium term): 6 months Median and range of days until RTW: 6 months Working hours per week: 6 months Adverse events (mortality, cardiac events, non‐fatal reinfarctions)
Identification	Sponsorship source: National Heart, Lung and Blood Institute, Bethesda, Maryland; Robert Wood Johnson Foundation, Princeton, New Jersey; Dr. Picard‐ National Research Service Award Fellowship Country: USA Setting: single‐centre, outpatient Possible conflicts of interest: no information provided Ethics committee approval: institutional review boards at Stanford University and Kaiser Foundation Hospitals approved the study
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomised using randomly sorted envelopes.
Allocation concealment (selection bias)	Low risk	Sealed envelopes were used to allocate participants.
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	RTW was assessed with questionnaires at 6 months or with an exit interview conducted by a data co‐ordinator. The researchers report that the data co‐ordinator had not been involved with performing the intervention, and this suggests an attempt to blind the outcome assessor.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: “All analyses were done by intention to treat.”
Selective reporting (reporting bias)	Unclear risk	Unable to determine, no study protocol was available
Other bias	Unclear risk	None identified