Abstract Purpose: To study the long-term effectiveness of case-management rehabilitation intervention among patients after myocardial infarction (MI) compared with the current standard of care.

Methods: Participants were 151 patients who underwent uncomplicated MI and of which nearly all enrolled in a cardiac rehabilitation program. Patients were randomized into an intervention or control group and provided two years of follow-up data. The intervention, conducted within an occupational medicine clinic, started during hospitalization or immediately thereafter and continued for 2 years. It included: early referral to an occupational physician, charting an occupational intervention program, coordinating between the patient and relevant parties, psychosocial intervention, intensive follow-up sessions during the first 1.5 months, and more spaced interventions during the follow-up period. Outcome variables were: return to work within 6 months of hospitalization and maintenance of employment at one and two years of follow-up.

The program was conducted by a clinical social worker within the OM clinic and included several components:

1. Intake by a CM covering information regarding the rehabilitating program, assessing the patients' perception of their illness and the impact of the event on their life and family. Also included were: familiarization with the patient's occupational background, assessment of motivation, expectations, perceived efficacy and difficulties concerning RTW, and the identification of areas of intervention. Referral to further evaluation and treatment by a psychologist/psychiatrist was up to the CM's discretion.
2. Referral to an OP was within one week of the intake.
3. Charting an occupational rehabilitation program and timing the RTW date, not later than 35 days from hospital discharge. Before their RTW date, patients were invited for an additional meeting with the CM to facilitate their readiness to RTW and make any necessary arrangements.
4. Coordinating between the patients and their family, treating physicians, the employer, community services, and meeting with the patient's family - all on a needful basis.
5. Provision of a guidance booklet for employers on the RTW of cardiac patients. Patients could read it by themselves and/or hand it to their employer.
6. The psychosocial intervention was tailored to the patient's emotional state, occupational needs, and specific requests. When needed, short-term (up to 4 sessions) psychotherapeutic treatment was provided to help alleviate anxiety and other debilitating concerns, illness misconceptions, family issues, and occupational wavering.
7. Intensive follow-up sessions aimed to ensure that the rehabilitation program was carried out as planned, were conducted 2-, 4-, and 6-weeks after the beginning of the psychosocial intervention.

Intervention during follow-up

1. Patients who had RTW within three months after discharge from the hospital, received follow-up calls as follows: two weeks from the start of the CM intervention, every two months during the first six months, and once every six months thereafter (as outlined above). If needed, one or more of the above interventions were applied.
2. Patients who had not RTW within six months after discharge, due to psychosocial or employer-related issues received up to 12 intensive intervention sessions, in which the relevant parties were involved. Upon successful RTW, the six months follow-up calls were resumed.
3. Patients who had not RTW after six months for the above reasons, and were assessed as having rehabilitation potential, were referred to the National Social Security rehabilitation services and were followed up monthly for one year. The CM intervention was ended for patients without rehabilitation potential. For both groups, follow-up calls continued for six months.

The study received ethical approval from the institutional review board, serial number 2006038.

Statistical analysis Results are presented as mean + standard deviation (SD) for continuous variables and as frequencies for categorical variables. Data were analyzed using the SPSS statistical package (Version 26, SPSS Inc., Chicago, IL). Student's t-test was used to test for a difference between the means of two groups on a continuous dependent variable. Chi-square test of homogeneity was used to test for a difference between two proportions. For small groups, it was replaced by Fisher's exact test.

A multiple logistic regression model was used to investigate the relationship between employment status (employed/unemployed) at one year and two years of follow-up and CM program participation. Adjustments were made for factors that were found in previous studies to be associated with vocational re-integration and that could have confounded the findings of this study. A list of the possible confounders is presented in Table 4. Significance was determined by p<0.05.

Inclusion Criteria:

• Sex/Gender: Both males and females
• Age limits: Minimum Age: 25 years old; Maximum age: 57 years old
• Clinical diagnosis: Patients after acute myocardial infarction
• Occupational status: Patients that have been working before the myocardial infarction
• HMO membership: Members in Maccabi Healthcare Service (HMO in Israel)
• Sampling Method: A consecutive participant sampling took place. Each patient who fulfilled the study terms was invited to participate in the study

Exclusion Criteria:

• Age over 57 years old or less than 25 years old
• Clinical diagnosis: Patients who had not sustained acute myocardial infarction
• Occupational status: Not working 6 months prior to the acute myocardial infarction
• HMO membership: Non-members of Maccabi Healthcare Service (HMO in Israel).
• Consent to participate: Patients who have not agreed to participate in the study

Owing to data privacy regulations, the raw data for this study cannot be shared.

The intervention group received a complex case-management rehabilitation program (described below) and the control group received the standard care.