Return to work after coronary artery bypass grafting and aortic valve replacement surgery: A scoping review

Background: Coronary artery bypass grafting surgery and aortic valve replacement surgery are essential treatment options for people suffering from angina pectoris or aortic valve disease. Surgery aims to prolong life expectancy, improve quality of life, and fa-cilitate participation in society for the individuals afflicted. The aim of this review was to explore the literature on work participation in patients following coronary artery bypass grafting or aortic


INTRODUCTION
Healthcare services play an essential role in improving the social participation of patients suffering from cardiovascular diseases (CVDs). CVDs include diseases of the heart and aorta, vascular diseases of the brain, and peripheral vascular disease [1]. Despite a roughly 50% mortality decrease from the 1980s to the early 2000s [2], CVDs still accounted for 20% of all deaths in Europe in 2016 [3].
Cardiac surgery patients in the working-age group most frequently undergo either coronary artery bypass grafting surgery (CABG) or aortic valve replacement (AVR). Older people with cardiac disease are frequently referred for less invasive interventions, such as percutaneous coronary intervention (PCI) or transcatheter aortic valve implantation (TAVI). CABG is the most common intervention in cardiac surgery and is performed on around 800,000 patients worldwide each year [4]. AVR was in 2003 around 290,000 operated patients [5], although this patient group is expected to increase to 850,000 by 2050 [6], as current low-income countries get better access to cardiac surgery. Thus, an increasing number of cardiac patients are excepted to be admitted to hospital to receive surgical procedures in order to sustain or improve life expectancy, quality of life (QoL), as well as social and occupational participation [7].
Unemployment and sickness leave are known to be expensive for society and have a negative impact on patients [8]. Work participation has been widely documented to improve a person's QoL and to be essential for a person's income, perception of personal identity, sense of accomplishment and capability of socialising with others. Consequently, work-related activities are central to human lives [9].
On the other hand, being unemployed or out of work due to illness has been shown to harm psychological health due to insecurity, stress, loss of dignity and lack of social belonging as a human being. Unemployment may lead individuals to experience loss of self-esteem and involuntary isolation [10,11]. Notably, patients suffering from CVDs and especially heart-related diagnoses (e.g. angina pectoris and myocardial infarction) have been reported to have a lower return to work rate compared to patients with other diagnoses [12].
The importance of employment among the working-age population, in combination with the societal need for a higher average retirement age in the future, make occupational rehabilitation and counselling a vital issue in cardiac care and in the curriculum of all health education programmes. Beyond survival, the role of nursing is to see the whole person and to integrate patient goals into the fundamentals of care [13]. Moreover, aftercare and nurse-led follow-up have been central to nursing and research [14]. However, work-related issues seem to be sparsely covered in critical care nursing literature as well as nursing literature in general.
Two previous reviews have been performed on the impact of cardiac rehabilitation on return to work after heart valve surgery. One is an overview, and the other a systematic review consisting of two articles with a small number of patients [15,16]. Hence, reviews that are broad in scope and summarise current evidence are warranted. This scoping review aims, therefore, to explore and describe the existing research literature on the return to work rate (RTWR) and the return to work time (RTWT), as well as factors related to return to work (RTW) in patients after CABG or AVR. By focusing this review on factors that hinder a RTW for this patient group, we may reveal the need for more knowledge and attention from nurses and healthcare personnel throughout the trajectory of treatment and rehabilitation [17]. Thus, this review addresses the following two research questions: 1. What is known about the RTWR and RTWT related to postoperative cardiac CABG and AVR surgery patients? 2. What are the clinical and demographic factors associated with RTWR and RTWT in postoperative cardiac CABG and AVR patients?

METHODS
Return to work is known to be related to both medical and non-medical factors [18]. The area is complex, and therefore a scoping study based on the framework of Arksey and O'Malley was chosen [19]. A broad literature search was conducted to explore both current knowledge and gaps in the existing research on the RTW after CABG and AVR. Furthermore, the review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews [20]. The Arksey and O'Malley framework has five stages, as presented below:

Stage 1 -Identification of the research question
In the first stage, we developed and operationalised our research questions to broadly explore the RTWR and RTWT, including facilitating and limiting factors, after first-time cardiac surgery. Research questions were developed, and based on these questions, we developed search terms and a search strategy. The PICO framework supported this process by creating a search focused on the population, intervention, outcomes and study design [21]. The research questions were discussed, and inclusion criteria were agreed upon with the whole multi-disciplinary research team.

Stage 2 -Identifying relevant studies
The systematic search for literature was conducted in collaboration with a health science librarian, using the following electronic databases: Medline, CINAHL, Embase and Google Scholar. The search was limited to the past 30 years (1st January 1988 to 31st December 2018). This time limit was discussed within the research group, and the exclusion was based on an anticipated declining relevance of study findings. Medical Subject Headings (MeSH) search terms and keywords were used with Boolean operators and appropriate truncations: thoracic surgery OR coronary artery bypass OR internal mammary-coronary artery anastomosis OR heart valve prosthesis implantation OR heart valve surgery OR heart valve replacement OR aortic valve surgery OR aortic valve prosthesis OR cardiac valve AND sick leave OR return to work OR back to work OR job re-entry OR work resumption. The database search was conducted between December 2018 and January 2019 ( Figure 1). Studies of patients who had undergone first-time CABG or AVR or a combination of these surgeries were included. The terms 'return to work', 'RTW', 'back to work' or 'job re-entry' had to be in the article. The language had to be English, Danish, Swedish or Norwegian. Only original articles were included, whereas opinion letters, systematic reviews and case studies were excluded. The literature search was updated in January 2020, but no recent articles matched the inclusion criteria.

Stage 3 -Selecting the studies
The software Rayyan [22] was used in the process of selection, which allowed total blinding between researchers (MM and ALM), thereby minimising the risk of bias. The initial search identified 624 articles from the database search. Following the removal of 192 duplicates, a total of 432 articles were transferred into Rayyan. First, a blinded pilot screening of titles and abstracts was performed on 20 randomly chosen articles in order to identify any needs for clarification concerning the inclusion process. The screening resulted in a conflict in five papers and better concordance in the subsequent inclusion process.
Next, the researchers (MM and ALM) performed a blinded screening on the titles and abstracts of the 432 identified articles. When opening the blinded mode, the revealed mode showed that 21.9% of the articles were included, 64.9% excluded, and 13.2% (57 articles) had a conflict. All conflicts throughout the screening process were discussed and consensus was obtained between the researchers. If an abstract was not available in Rayyan, the article was identified from the databases directly and selected according to the same criteria in order to determine if the article was relevant or not. The screening resulted in 108 articles being eligible for a full-text review. Two researchers (MM and ALM) independently read through the full text of all included articles. As with the title and abstract screening, conflicts were resolved through discussion and finding consensus. Full-text arƟcles assessed for eligibility (n = 108) 63 Full-text arƟcles excluded because they were: -not a scienƟfic study (n = 6) -not English language (n = 5) -not return to work outcome (n=52) Studies included in scoping review (n = 45) Updated search January 2020 Total (n=0)

RETURN TO WORK AFTER CARDIAC SURGERY
Being a scoping review, the researchers did not perform a quality appraisal. Overall, we identified 45 articles for final inclusion, as shown in Figure 1. The identified articles were made available for the rest of the research team. For final inclusion of the studies, return to work had to be an outcome in the articles.

Stage 4 -Charting the data
We chose a narrative review approach and after reading the 45 articles, the researchers charted the information in a table in order to categorise critical design issues and study findings (Tables 1 and 2). The obtained data were entered into the programme Excel.
The information in the data charting form was collected and sorted as follows: -Author(s), year and country -Aim of the study -Design -Study population (age, sex, surgical treatment, mean age) -RTWR -RTWT -Positive factors for RTW -Negative factors for RTW

Stage 5 -Collating, summarising and reporting the results
The process of collating and summarising the results was based on the information in the charting table. We followed the Arksey and O'Malley framework, with two distinct steps: fundamental numerical analysis followed by a synthetic and thematical analysis [19]. In the first step, a narrative account of the data was performed by describing the number of studies, their geographical distribution, research methods, RTWR and RTWT [19]. This step included a descriptive numerical summary analysis in determining the proportion of patients returning to work. The percentage of patients that returned to work was calculated by dividing the total number of patients returning to work through all studies by the total number of patients included in the studies. Furthermore, the overall RTWT was calculated as the weighted average throughout the studies, where this information was available using the number of patients in the study as the weighting factor.
In the second step, factors that facilitated, limited or delayed the patients' return to work were synthesised thematically [19]. Limiting and hindering factors and the summary of RTWR/RTWT became the primary unities of our narrative review. In the following, findings from the articles are presented based on the thematic summary of the results.

Setting and sample
The review identified 45 articles representing a total of 39,801 patients being treated with first-time CABG or AVR. The mean age of the patients was 56.3 years (SD ± 7.3), and 16% were women. They had mainly undergone CABG surgery (n = 39.621), whereas a single study included AVR patients (n = 139) and also approached patients after they had been offered both surgeries (n = 41) [23].

Return to work rate and return to work time
Patients were either employed, on sick leave or out of work at the time they were included in the studies. On average, 66.5% (13%-93%) (n = 34) resumed employment after surgery, and the mean RTWT was 30 weeks (9.3-36 weeks) (n = 14).

Clinical factors associated with return to work
Clinical factors predicting an increased RTWR were normal ejection fraction [38,39,61,64], and the absence of angina pectoris, as well as the absence of chest pain after surgery [41,45,47,50,52,53,55,63,67,68]. Patients with significant comorbidity (e.g. diabetes, chronic obstructive pulmonary disease, renal failure, dyspnoea, atrial fibrillation and cerebral vascular diseases), as well as a severe dysfunction according to the New York Heart Association (NYHA) Functional Classification system, were less likely to RTW [24,28,37,39,41,47,55,61,64]. The Duke Activity Status Index (DASI) for measuring functional capacity has been demonstrated to correlate with the NYHA classification. Patients that were not working due to cardiac complaints and a high NYHA class also scored low on DASI [28]. A single study from Iran in 2016 identified four new medical factors that could be used as predictors of early RTW after CABG [43]. The study found that normal serum troponin and high levels of serum magnesium at admittance, normalisation of blood pressure before surgery (Middle Arterial Pressure (MAP) ≤90 mmHg), and a shorter extracorporeal pump run time during surgery with a mean of 64.3 min, were associated with early RTW. A relatively longer RTWT was observed in the group that had a mean pump run time of 78.8 min [43].

Psychological predictors for return to work
The impact of anxiety and depression on peoples' lives was confirmed, with pre-surgery depression shown to be a negative predictor for RTW [51,54]. Depression was found to be prevalent among individuals undergoing cardiac surgery [41,51,54,55]. One particular study reported that 47% of 141 CABG patients were psychologically depressed before surgery, whereas 61% were depressed after surgery or prior to discharge from the hospital [69].
Illness and being out of work have an impact on the patient's QoL after surgery. This was demonstrated in a Norwegian study showing coronary disease patients undergoing PCI or CABG and who RTW had a stronger internal locus of control beliefs than those who did not RTW [59]. Furthermore, several studies reported that patients who RTW after surgery had a significantly increased QoL compared to those who did not resume working [43,49,54,66,67]. On the other hand, patients that had a low score on the self-reported Short Form Health Survey (SF-36) or a QoL questionnaire and also had negative health perceptions were less likely to RTW [66].

Socio-demographic, economic and occupational predictors for a return to work
The socio-demographic factors that predicted a higher RTWR were being male [24,41,46,49,66] and being of younger age [24, 37, 41, 43, 47, 49-52, 61, 64]. Several of the studies found that patients with a 'white-collar' job as opposed to a 'blue-collar' job [41,43,47,49,52,55,63,66] were more likely to RTW after surgery. A 'white-collar' job refers to a job that mostly or entirely involves mental work or desk work, for example, in an office. 'Blue-collar' job refers mainly to manual jobs, such as artisanship and factory work.
Three of the studies included in the review illustrate that the region from which the patients originate may be a predictor of RTW. One study from Italy and one from France observed that patients from southern Italy and south-eastern France, respectively, were less likely to RTW [47,52]. In a Norwegian study [63], it was observed that a relatively large number of patients domiciled in rural parts of Norway resumed work after surgery as compared to patients originating from urban areas.
Furthermore, income and education levels seemed to have an impact on RTW as patients with a higher income, or a higher education level resumed work more often [24,40,51,52,59]. Employment before surgery has repeatedly been recognised as necessary to increase the probability of later employment, while unemployed patients or those on sick leave before surgery are less likely to RTW. In other words, feelings of job security and employment before surgery are likely to be two of the strongest predictors associated with a high likelihood of a RTW [23,24,35,41,43,52,53,61]. The patient's own expectations of returning to employment were found to be of importance. When the subject of work and returning to work is orally communicated to the patient by hospital healthcare personnel, it has been demonstrated that this has a strong correlation to whether the patient returns to work or not [34,38,41,70].
Cardiac rehabilitation is often offered to patients after surgery and consists of physical training, education and social support [71]. Some patients in the studies were transferred directly to a specific cardiac rehabilitation centre after discharge from the hospital. Participating in cardiac rehabilitation improved their health-related quality of life (HRQOL) [49] and was related to an increase in physical work capacity, less use of anxiolytics, fewer readmissions, and generally improved physical health [44].

DISCUSSION
Cardiac surgery is each year offered to a significant number of patients each year [4,5]. Even so, it is a scarcity of reviews summarising the impact of surgery on the patients' return to work. This scoping review considers both periods of working absence after CABG or AVR surgery, as well as the different components, hindering or facilitating RTW after surgery. The purpose of this scoping review was both to summarise current evidence and to identify current gaps in knowledge gaps.

Articles included
The majority of studies concerning return to work were conducted in Europe, followed by the USA and Australia. No studies were identified from the African continent, and only three originated from Asia. This may suggest that there are differences in research possibilities that could reflect dissimilarities in health care systems as well as employment on these continents. This was confirmed in previous studies from Europe and the USA, which are at the forefront in return to work research [72].
All of the included studies were of quantitative methods, except for one study that had a mixed approach. From the sample and setting we used, qualitative studies describing the patients' own stories and opinions on returning to work from a more humanistic perspective, were absent.

Impact of CABG and AVR surgeries on return to work
Given that 20% of deaths in Europe are related to heart disease, this patient population is a substantial cohort that healthcare personnel often encounter in hospitals and primary care settings. The findings in this review identify several at-risk groups whose RTWR is lower than for other patient groups. In terms of RTW in cardiac surgery patients and RTWR, the review revealed that most patients RTW even though 34% do not. The time on sick leave varies across the studies, and our review found an average time of 30 weeks, with a minimum time away of nine weeks and a maximum of 36 weeks, among those who RTW.
The postoperative period after cardiac surgery is known to be troublesome for many patients, caused by pain and restrictions on carrying heavy weights or using their arms due to the sternotomy. A Danish article claims that patients are recommended to be on sick leave for 4-8 weeks following a sternotomy [73]. The difference in RTWT between this medical recommendation (4-8 weeks) and what is found in the present review (30 weeks) is significant. However, a Swedish study discovered that patients with severe cardiovascular problems have lower RTWR in general [12]. Additionally, each country has its own set of rules and regulations when it comes to sick leave after surgery [74]. It may be that countries with stricter regulations on sick pay or countries that do not have statutory sick pay, have shorter RTWT than countries with more permissive regulations [75]. After surgery, some patients are transferred to cardiac rehabilitation (CR). The role of CR is found to be a positive factor in some studies with improved HRQOL and general physical health in patients [44,49]. Reviews on valve surgery and participation in CR have shown conflicting results, and it has been found that RTW was facilitated after CR [16]; in contrast, another review found no significant difference between those who participated in CR and the patients who did not [15]. More research is granted on the role of CR directly linked to RTW in both CABG and AVR patients.
There is increasing awareness that the longer patients stay off work, the less likely it is they will RTW. Research has shown that in general, returning to full employment decreases significantly after 6 months of sick leave, and the probability of ever returning to work falls to 50 per cent by the third month after injury or illness [75]. Moreover, there has been a shift from medical models to more holistic models combining medical information with workplace, cultural, economic and social factors in our understanding of RTW after illness [76].

The patient's stay in the cardiothoracic surgery intensive care unit
Cardiac surgery is associated with severe risks of postoperative complications such as bleeding, circulatory instability and general inflammation response, hence patients are referred to postoperative surveillance in Cardiothoracic Surgery Intensive Care Units (CTICUs) [77]. In some single studies, clinical predictors of complications were measured and identified, such as serum troponin-T levels and shorter time of extracorporeal bypass circulation. However, there were few such studies, and they only took into account specific measurements [43]. We identified a knowledge gap in the postoperative phase and particularly in what happens in the CTICU. Factors such as ventilator time, length of stay in the Intensive Care Unit (ICU) and delirium are known to increase cognitive, mental and physical side-effects of ICU treatment and further studies is needed to examine the impact of the ICU treatment on RTW [78].

Impact of demographic factors associated with return to work after surgery
Several demographic factors are correlated with the RTW after surgery, such as age, sex, economic status, area of residence, type of professional work and education level [24,52,59,61,66]. Women accounted for only 19% per cent of the sample in this review. In a Finnish study, it was demonstrated that women tend to have a lower RTWR than men after cardiac operations [61]. The study concluded that in the general population and within different health problems such as CVDs, women also had more prolonged periods of sick leave than men [79]. Women have been known to be a missing group in cardiology research [80]. Even though ischaemic heart disease accounts for a third of all female deaths globally, women are still underdiagnosed and are less likely to receive appropriate treatments [81]. A recent study also indicates that female sex was associated with long-term mortality after cardiac surgery [82]. The reasons behind the gender difference with regards to RTW have not yet been identified, and more research is warranted within this field.
Differences were identified between 'blue-collar' and 'white-collar' workers in the present review. While 'white-collar' workers have a higher RTWR than 'bluecollar' workers, it is essential to keep in mind that 'bluecollar' workers have traditionally more manual and more physically demanding jobs. The lifting restriction after surgery has an impact on when these patients RTW. Engaging in manual labour after a recent sternotomy could be difficult and may explain the difference in the RTWT between these two groups of workers. The rehabilitation time may be three months for patients resuming office work, but the double for those with a physical demanding workload. In this matter, a mini-sternotomy approach may be beneficial in some patients with AVR as compared to a full sternotomy [83]. Transcatheter aortic valve implantation could theoretically be an advantage for earlier RTW after AVR, but in the younger population, this is still not accepted as good medical practice as compared to a surgical AVR [84].
The patient's level of education was identified as a contributing factor for returning to work after surgery. Several studies concluded that higher education had a positive correlation with the RTW. Given that most 'blue-collar' workers have lower secondary education, both lower education and the nature of the work could be negative factors for this group when it comes to returning to work. The educational factor has several elements, such as the difficulty for patients with a lower education to enter, stay in or re-enter the labour force due to poorer physical health and the nature of the work [85]. Secondly, patients may not have the psychological means to be able to find or remain in employment due to inadequate or reduced health [86]. Moreover, the negative impact of a low level of education, and poor physical and mental health on work-life participation are highest in a person's late work-life [87].
Another predictor that has been identified in three studies is the patient's geographical residence. In two of the studies, one from France and one from Italy, researchers found that in lower gross domestic product (GDP) rural regions of these countries, patients had a lower RTWR than within the rest of the country per capita [47,52,88]. As GDP is higher in populated areas than rural areas, we also find this phenomenon in Norway when comparing rural regions with urban regions. Surprisingly, in a study from the middle part of Norway the opposite was found, that is a higher number of patients from rural areas RTW after surgery than in the urban areas [63]. Further studies could be of interest by identifying the link between economy, geographic location and RTW. However, the patient's private financial condition seems to be closely linked with RTW.

Return to work after CABG and AVR surgery and its association with quality of life
Work and work participation have previously been described as crucial to patients' QoL but are also significant on a socio-economic level; thus, helping patients back to employment after surgery is of great importance. Furthermore, there has been a change in how society perceives being out of work and it is a multifactorial issue affected not only by the patients but also by the different systems in a country [76]. Studies show that employment is essential for a more rapid recovery and for both the physical and mental health of patients [89]. Previous studies have also shown that prolonged sickness absence tends to make RTW less likely, especially in women [90]. Moreover, long-term sick leave has been related to increased mortality in both sexes [91][92][93].
Our review found that patients' QoL increased after surgery, and those with a higher QoL went back to work faster or more often than those with a low QoL. Notably, returning to work has been related to return to a stronger internal locus of control beliefs, indicating that patients believed they could influence events and their outcomes positively after cardiac surgery [59]. Providing adequate information to patients, however, is a paradox, as we know that the time the nurse spends with patients is decreasing and has been reported to be as low as just 37% of the nurses' time during a single shift [94]. Theoretically, communication and employment information when meeting with the patient could have an impact on RTW [34,38,41,70].

The importance of nurses in the multidisciplinary care of the post-cardiac surgical patient
Meetings between a patient and a nurse are unique and diverse, and nurses meet and interact with patients in all stages throughout the hospital stay. In these meetings, trust and interaction are established in a nurse-patient relationship that is important for further care and treatment; hence, the relationship is the core of the fundamentals of care framework by Kitson [13]. The nurse has a unique role in caring for cardiac patients, from admission, through critical care nursing in the CTICU, to discharge, and finally, in the setting of cardiac rehabilitation. In these encounters, the awareness of work status should be given priority in nurse-patient communication. The RTW counselling in cardiac rehabilitation has been demonstrated to be lacking and is highlighted as an important measure that needs to be more consistently delivered to this patient group [95]. A more holistic approach to discharge planning and aftercare, tailored to each patient's physical and psychosocial health, their social and cultural context, resources and limitations, is central to nursing.
Besides, a closer collaboration between clinicians and researchers, as well as a more robust curriculum in both medical and nursing educations with emphasise on work and the importance of work for their patients, could improve RTWR after CABG and AVR in the future. Moreover, more seamless collaboration between health professionals working in inpatient and out-patient settings is needed.

Implications of the study
The bio-medical perspective is imperative for patient survival in cardiac surgery care. However, patients should be viewed in a larger context, and nurses have to conduct integrated care of the whole patient [13]. Nurses have a close interaction with patients and their families and the rest of the multi-disciplinary team, and therefore a special responsibility to establish plans beyond hospital care. Our study results can impact several levels, such as both the education and clinical training in nursing. These findings can be useful for students and experienced nurses. In a clinical setting for nurses, new educational objectives could be implemented, such as raising a more direct focus on patient's employment and knowledge on RTW before leaving the hospital by a nurse-led conversation. Students in universities should be sensitised to learn more about RTW in cardiac surgical patients and the importance of RTW for all patient groups as a concept. Furthermore, the lack of knowledge on this topic indicates that more research is warranted to prevent long-term unemployment and improve care and follow-up after cardiac surgery.

LIMITATIONS AND STRENGTHS OF THE REVIEW
There are limitations to the findings of this review. It is possible that relevant articles were unidentified, even though the correct search terms were used. The search was only performed for English and Danish, Swedish and Norwegian languages, meaning that there could be articles in other languages that may provide additional insight into the subject.
Even though an RTW has been claimed as a reliable endpoint [96], directly measuring the first RTW does not describe the stability of work participation. Throughout the articles, several endpoints and follow-ups have been observed from 6 months up to 10 years. A limitation is that each country has its own set of rules and regulations when it comes to sick leave after surgery, and this could have an impact on the observations found in this review. Based on the results of our study, it seems that patients tend to stay on sick leave for longer than expected, and this has to be taken into account when deciding what follow-ups should be applied in future studies.
The strengths of our review were that we used blinded mode when screening articles in Rayyan, minimising the risk of bias. Furthermore, researchers repeated the search in January 2020 before submitting this article in order to identify new articles published during the year.

CONCLUSION
The postoperative rehabilitation phase after cardiac surgery is known to be demanding for patients, and it takes time until the patients are fully recovered. However, our review showed that the average RTWT across studies was significantly longer compared to the time indicated in the pre-operative information that was given to patients. Older patients, female patients, patients with previous psychological depression, and those with a low income and low level of education seem to be at higher risk of work absence and require more extended sick leave than other patient groups before resuming work. A multi-disciplinary and systematic approach is needed to identify patients at risk of no return or delayed RTW after CABG and AVR. Moreover, professional counselling should be part of the standard follow-up after cardiac surgery. The role of the nurse in assessing work-related issues before and after surgery is important from the perspective of the fundamentals of care. Even so, more knowledge is needed on specific interventions to improve RTW after CABG/AVR surgery. Thus, it is time to look beyond survival and to focus more on improved quality in nursing care aiming at higher resumption of work after cardiac surgery.