Introduction
Cardiovascular disease, already the most common noncommunicable disease in the Middle East, is continuing to increase in prevalence in the region, with Iran among those countries with the highest prevalence rates (Moazzeni et al., 2021). Despite advances in medical science and equipment, coronary artery bypass graft (CABG) surgery remains the standard strategy for the treatment of advanced coronary artery disease (Palmerini et al., 2017), accounting for 78.8% of all cardiac surgeries in Iran (Akhlaghi et al., 2020).
Anxiety is a major problem in patients scheduled for heart surgery and is more prevalent in heart surgery than other surgeries because proper heart functioning is critical to the continuance of an individual's life (Hinkle & Cheever, 2013). The results of a meta-analysis by Takagi et al. (2017) indicate that prolonged anxiety in patients scheduled for cardiac surgery may be associated with a higher risk of postoperative mortality. Preoperative anxiety may increase the risk of postsurgical lesions, including atrial fibrillation, acute myocardial infarction, increased disease and mortality, and increased use of healthcare. In addition to being a distressing state, anxiety is a common denominator of many physical and mental disorders. In fact, for most illnesses and physical and mental disorders, anxiety is considered a major discomfort. In addition, anxiety in patients experiencing chronic and prolonged disease may cause major destructive physiological changes (Alipoor et al., 2014). Tully et al. (2015) found that patients with high levels of anxiety have a higher risk of death before CABG surgery. Moreover, Middel et al. (2014) showed a positive relationship between preoperative anxiety and postoperative anxiety after CABG surgery. In addition, they showed that identifying patients with high anxiety would help healthcare providers offer specific interventions to reduce their anxiety and improve their quality of life.
Helping patients adapt to anxiety is a major responsibility of nurses. Nurses play an important role in preparing patients emotionally and psychologically during the preoperative period of cardiac surgery. Therefore, nurses should always look for ways to improve the quality of nursing care (Ramesh, 2017). In this regard, applying nursing theories and models in the advanced practice area of nursing may be beneficial for patients (Reed, 1993).
One of these models is the Neuman Systems Model (NSM), which is an open model-based perspective that provides proper function in stressful situations or at the time of the patient's response, which is recognized as a priority in nursing (Meleis, 2011). The NSM is based on an individual's relationship with and response to stress. The three key concepts of this model are stress, homeostasis, and patient's perception. The role of the nurse is to focus on the factors influencing the individual's response to stress and protecting the patient from the relevant risk factors (Heffline, 1990). In this model, the main goal of nursing is to maximize patient well-being by using nursing care to reduce stress. The nurse creates a relationship among the patient, environment, and health to establish a sustainable system. It is necessary for the nurse to evaluate the patient's perceived stressors to improve patient stability. As the relationship between the nurse and patient develops and mutual understanding improves, differences in understanding may be eliminated. The outcome of this partnership is complementary within a joint care plan that may be implemented with a clear objective in mind (Parvan et al., 2012).
Under the NSM, nurses are considered to be active contributors (Smith & Parker, 2015), and prevention is pursued as one of the most important nursing interventions to protect the patient. In this model, the goal of nursing is to strengthen a patient's defenses, improve their health, and, ultimately, improve their ability to cope with health issues (Meleis, 2011; Parvan et al., 2012). The main point is the importance of providing nursing care in the form of prevention levels. Primary prevention aims to prevent tension agents from penetrating defensive lines by reducing stress and strengthening defense lines. Secondary prevention attempts to increase goodness, reduce stress, and reinforce coping by strengthening defense lines. In fact, the goal of secondary prevention is to maintain the level of coping (Fawcett & Garity, 2008; McEwen & Wills, 2017).
Nursing interventions seek to reduce the stressors and situations deemed to affect or potentially affect the patient's desirable factors. The distinction made between the prevention levels in nursing interventions designed to reduce stress is one of the benefits of the NSM. Another advantage is its focus on prevention levels that are more socially acceptable because the community is progressively aware of the significant role of nurses in the healthcare system. A further strength of this model is its flexibility as a stimulus-response systems model that considers the basis for development of the theory and evaluates the relationship between nursing theory and clinical research and practice (Sultan, 2018).
Nursing theories should be developed with the goal of promoting practical applications in clinical practice. Developing and reviewing theories have the potential to open up new approaches to quality care that may challenge the current care system (Wadensten & Carlsson, 2003). Nursing is not only a practical discipline but also a knowledge-based profession. Therefore, to create new practical approaches, having the foundation of knowledge is one of the requirements in this field (Aghebati et al., 2012). There is a gap between theory and practice in the nursing profession, and nurses focus more on the practical aspects of nursing than on nursing science and art (Mrayyan, 2006). Moreover, the need to reduce anxiety using holistic care models in patients undergoing CABG is addressed in this article. This is an issue that has been insufficiently addressed in the scientific literature, especially in non-Western countries. Therefore, the existing gaps encouraged the development of a research project aimed at evaluating the effect of applying the NSM for anxiety in patients scheduled for CABG surgery.
Methods
Design
This study was a single-center, single-blinded, two-armed, randomized controlled trial conducted in an urban area of Iran from October 2017 to August 2018.
Participants and Sampling
Participants' inclusion criteria for this study were as follows: being a candidate for CABG surgery, having full consciousness, admitted at least 1 day before surgery, willing to participate in the study, able to communicate in the Farsi language, and aged 30-70 years. This age range was selected based on the rare number of candidates below 30 years old and in accordance with the literature, which has shown a significantly negative correlation between age and anxiety, as patients older than 70 years have been found to report the lowest level of anxiety before and after CABG surgery (Krannich et al., 2007). The exclusion criteria were as follows: discontinuing the patient's participation at any phase of the study, an emergency condition that required giving medical care to the patient during the intervention, and any delay in surgery (e.g., because of financial problems, not providing consent for surgery, deteriorating health condition). The minimum sample size required was 32 participants in each group based on Nasiry Zarrin Ghabaee et al. (2015), which applied the NSM to reduce the level of anxiety in orthopedic patients before surgery. In this study, the required sample size was determined with a 95% confidence and 80% test power, and the mean standard deviation of anxiety score was estimated in both groups. The final, target sample size was determined to be 35 people in each group in this study, considering a potential dropout rate of 10%.
Patients who were referred to the cardiology center and were waiting for surgery enrolled in the study using a convenience sampling method based on eligibility criteria. Of the 75 total potential participants, 70 were randomly assigned to either the intervention group (n = 35) or the control group (n = 35) using the following cards/envelope shuffling method (Kim & Shin, 2014). First, code "A" was assigned to the intervention group, and code "B" was assigned to the control group. Then, the researcher (first author) wrote letters A and B on cards and placed them in an envelope. Next, each of the enrolled participants was asked to take one of the envelopes. Those who took an envelope containing Card A were included in the intervention group, and those who took an envelope containing Card B were included in the control group (Figure 1). The researcher (first author) implemented the intervention and collected the data.
Data Collection
A sociodemographic data questionnaire, the Revised Cardiac Surgery Stressors Scale (RCSSS), and the State Anxiety Inventory were used for data collection.
The sociodemographic data questionnaire was designed by researchers using a review of the literature and either self-completed by the participants who were literate or completed during the interview by the researcher for participants who were illiterate.
The State Anxiety Inventory questionnaire contains 20 questions scored on a 4-point Likert scale. Reverse ratings were applied for negative items, and a total score was calculated, ranging from 20 to 80, with score ranges categorized as low anxiety (20-37), moderate anxiety (38-44), and high anxiety (45-80). This questionnaire has been translated into 30 languages and has been adapted to suit the Iranian cultural setting. In this study, Cronbach's alpha ([alpha]) was calculated to assess the internal consistency reliability of the translated instrument, with the result of .97 indicating sufficient internal consistency based on a recommended level of > .70 (Spielberger, 2010). This questionnaire was completed by/for all of the participants at three points in time: before the intervention, immediately after the intervention, and at discharge time.
The RCSSS includes 37 questions, and the second part includes RCSSS cases in three subgroups: intrapersonal stressors, including 11 phrases; interpersonal stressors, including nine phrases; and extrapersonal stressors, including 17 phrases. The items were ranked according to the level of concern of the participants on a Likert scale from 0 to 4, with 0 = no worries, 1 = very low worries, 2 = low worries, 3 = moderate worries, and 4 = worries. The lowest scale score of 0 indicates the absence of stressors, whereas the maximum score of 148 indicates the highest stressor factor, with ranges of 0-37 indicating very low stressors, 38-74 indicating low stressors, 75-110 indicating the presence of relatively stressful factors, and 111-148 indicating stressful factors. The reliability of this questionnaire was calculated using Cronbach's alpha coefficient (patient = .81; nurse = .93) in previous research in the Iranian context (Parvan et al., 2013). In this study, the reliability of the RCSSS calculated using Cronbach's alpha was shown to be adequate (patient = .82; nurse = .91). This scale was only used to categorize patients based on level of prevention.
Intervention
First, the potential and actual stressor factors for each patient, including intrapersonal, interpersonal, and extrapersonal, were evaluated using the RCSSS (patient part; Parvan et al., 2013). Second, appropriate goals and strategies for action were determined. If no actual stressors were found, interventions at the first level of prevention were carried out, and the influence of the stressors on the natural defense line was prevented by reducing the probability of exposure to stressors and strengthening the defense line. If stressors were identified based on the patient part of RCSSS, these factors were known as actual stressors, and the patient was placed in the second level of prevention. If different levels of stressors were identified, the RCSSS (nurse part; Parvan et al., 2012) was also completed by the responsible shift nurse to determine the patient stressor. The nurse's perception is considered as one of the steps of the NSM in relation to the patient's stress factors. On the basis of the study of the second level of prevention, the intervention was identified to reduce the stressors that caused damage to the natural and flexible defense line. The intervention was aimed at strengthening internal defense lines to reduce the reaction. In the presence of the stressors, the intervention continued at the third level of prevention after surgery using Benson's relaxation method. The main goal of the tertiary prevention component of the NSM is adaptability (Fawcett & Desanto-Madeya, 2012; Sahrakhil et al., 2017). To implement the Benson's relaxation procedure, patients were placed in a relaxed environment and in the most comfortable position. Then, they were asked to choose a calming word and take comfortable, deep breaths. They were asked to inhale through their nose and repeat their calming words during exhalation through their mouth. During this process, patients were asked to relax all of the muscles in their body from head to feet (Sahrakhil et al., 2017).
Prevention of the first and second levels was done in one or two 45- to 60-minute consecutive sessions before surgery. The first session was implemented on the day of admission in the morning or evening shift. The second session was implemented during the evening or night shift. The conversations were held individually at patient bedsides under conditions considered favorable by both patient and researcher. The contents of these conversations included a self-introduction, the purpose of the research, and a simple explanation about coronary artery anatomy, preoperative cardiac surgery, the operating room and intensive care unit, and postintensive care unit cardiac and postoperative orders and care (Table 1). At the end of the first session, an educational booklet on the issues discussed was given to the intervention group. Moreover, the patient's companion in the intervention group received the care program from the researcher 1 day before the surgery based on the NSM. Of the 32 participants in the intervention group, 28 were assigned to the first and second levels of prevention and received the preoperative intervention. Only four received the third level of prevention. Preventive level assignments were determined based on the presence of stressors identified through the questionnaire on the revised cardiac surgery stressors (patient part). The participants assigned to the control group received usual care only.
Ethical Considerations
Ethical approval for this study was obtained from the Vice-Chancellor of Ethics of Research and Technology of Isfahan University of Medical Sciences (reference no: IR.MUI.REC.1396.3.838) and the Iranian Clinical Trial Center (reference no: IRCT2018011603897N1). The managers of the research settings were notified of the aim of this study and that participation would not result in any harm or difficulty. The participants were informed about the aim and procedure of this study and that data would be kept confidential. Finally, an informed consent form was signed by those who consented to participate.
Data Analysis
SPSS software Version 22 (IBM, Inc., Armonk, NY, USA) was used for data analysis. Frequency and percentage for qualitative variables and mean and standard deviation for quantitative variables were applied using descriptive statistics to describe these variables. In addition, the chi-square test, Fisher's exact test, and an independent sample t test were conducted to find differences in sociodemographic variables between the two study groups. In addition, an independent sample t test was used to compare the mean anxiety scores between the intervention and control groups before the intervention, immediately after the intervention, and at discharge time. This test was also used to compare the mean RCSSS scores of patients and nurses. Moreover, the one-way repeated measures analysis of variance (ANOVA) test was applied to evaluate changes in mean anxiety scores over time in the two study groups and to compare mean anxiety over time in the intervention group. A p value < .05 was regarded as significant.
Results
As shown in Figure 1, of the 70 participants, three from each group were excluded from the final analysis because of exclusion criteria (n = 64). The mean age of participants in the intervention and control groups was 60.72 and 57.23 years, respectively. Most participants in the intervention (68.8%) and control (59.4%) groups were male. Other sociodemographic variables are listed in Table 2. There were no significant differences in sociodemographic variables between the two groups (Table 2).
As shown in Table 3, the results of RCSSS showed that no significant differences were present between the mean scores of the intervention and control groups (p = .59, t = 0.54). Regarding patients' and nurses' perspectives on RCSSS, the mean scores of the nurses were significantly higher than those of the participants (p < .001, t = 7.60; Table 3).
As shown in Table 4, no significant difference was found in preintervention mean anxiety scores between the two groups (p = .48, t = 0.71). The level of anxiety was moderate in the control group (42.40) and in the intervention group (44.27) before the intervention. However, the mean anxiety score in the intervention group was significantly lower immediately after the intervention (p = .008, t = 2.73) and at discharge time (p = .007, t = 2.77) than in the control group. Moreover, the one-way repeated measures ANOVA for each group revealed that the mean anxiety scores statistically significantly reduced over time in the intervention group (p = .001, F = 11.34) but not in the control group (p = .18, F = 1.79).
In the intervention group, the result of Fisher's least significant test after one-way repeated measures ANOVA showed that the mean anxiety score in the intervention group was significantly lower immediately after the intervention (mean difference [MD] = -6.61, p = .001) and at discharge time (MD = -7.81, p < .001) than before the intervention, with no significant difference found between immediately after the intervention and at discharge time (MD = 1.21, p = .33). On the basis of the results of the independent sample t test, at discharge time, no significant difference was identified in terms of anxiety scores between participants who received the first and second levels of prevention and those who received all three levels of prevention (p = .34, t = 0.95).
Discussion
The aim of this study was to investigate the effect of applying the NSM on anxiety in patients scheduled for CABG surgery. The findings revealed that using this care program based on this model had a significant effect on reducing anxiety in these patients.
Although there have been some discussions regarding the effect of nursing theories in practice, the value of using nursing theories for the advancement of the nursing profession has been supported in the literature (Bourdeanu & Dee, 2013). Theories and models of nursing provide a coherent and systematic framework to guide nursing assessments, planning, and interventions. In addition, theories and models can help generate more knowledge and differentiate what should be the basis of nursing practice (Polit & Beck, 2004). Furthermore, models can help nurses provide better care to patients (Huang et al., 2015). In this study, the NSM was used to provide care to patients.
The results of a previous study conducted on candidate patients for orthopedic surgery showed that using the NSM reduced the anxiety level in patients waiting for surgery (Nasiry Zarrin Ghabaee et al., 2015). Moreover, the finding of another study indicated that applying this model may reduce the level of stressors in patients scheduled for CABG surgery. In addition, providing care based on this model can effectively diminish the incidence of anxiety in patients with gastrointestinal malignancy, endometrial carcinoma, and lung cancer (Wang et al., 2019). The results of the reviewed studies are consistent with the results of this study.
In this study, patients reported a lower perception of stressors than nurses. This finding is consistent with the results of a previous study (Parvan et al., 2012). The misunderstanding of nurses may have an adverse effect on nursing care and induce stressful symptoms in patients during nurse-patient communication. Nurses should avoid applying their preconceptions in determining the severity of patient stressors (Parvan et al., 2012).
Studies have shown that the functional and psychological status of patients worsens when they are placed on the cardiac waiting list because they do not know what to expect (Guo, 2015; Rosenfeldt et al., 2011). At the same time, many nurses responsible for the care of candidate patients for heart surgery are not aware of the benefits to patients of preoperative interventions. Thus, they focus on postoperative interventions only (Alshvang, 2018). A substantial part of the NSM revolves around internal and external stressors, with an emphasis on patient education (Neuman & Fawcett, 2002). In this study, the intervention program was designed based on the NSM in the first and second levels of prevention. It was delivered to patients individually after identifying patient stressors during teaching sessions. Providing an educational booklet was also found to reduce anxiety level. In agreement with this study, a randomized controlled study by Guo et al. (2012) found that a preoperative educational intervention was effective in reducing anxiety in cardiac surgery patients. The results of another study showed nurse-initiated preoperational education and counseling to be associated with a reduced level of anxiety after CABG surgery (Zhang et al., 2012). However, according to the results of a recent systematic review, further research is required to investigate preoperative educational intervention effects in cardiac patients, especially in non-Western countries (Guo, 2015).
The NSM applies a holistic vision to discover the effects of stress on patients as well as to improve patient capabilities to adjust and rebalance (Verberk & Fawcett, 2017; Wang et al., 2019). Although the effect of this model has not been investigated in patients undergoing CABG surgery, the application of this model has been documented in the care of patients with various diseases. Ahmadi and Sadeghi (2017) suggested that this model be applied as a framework to assist nurses in the care of patients with multiple sclerosis. In addition, Wang et al. reported that the NSM is applicable to the care of patients with cirrhosis, patients with cancer, patients with hypertension, and patients with stroke.
The findings of this study show no difference in the intervention group at the time of discharge in terms of the level of anxiety between those who received the first and second levels of prevention and those who received all three levels of prevention. The aim of the first and second levels of prevention in the NSM is removing stressors, whereas the aim of the third level of the intervention is adapting to the stressors. Therefore, it should be considered that the stressors were still present in the participants who received the third level of prevention. This may be attributed to individual differences in terms of psychological or family status (Sedaghat et al., 2019). According to the findings in this study, adaptation using a relaxation method as the third level of prevention may be an effective intervention to reduce anxiety in patients scheduled for CABG surgery. However, the use and interpretation of our findings should be done with caution because these results may be attributable to the small number of participants who received all three levels of prevention.
Limitations
There were a number of limitations in this study. First, this study was performed at a single center using a small sample size. Second, although participants filled out the questionnaires in a low-stress environment, issues such as boredom and financial or family conflicts may still have occupied the thoughts of the participants and influenced their responses. Third, although the researchers tried to keep the participants in the two groups unaware of the identity of the intervention, participant ascertainment and observer bias may have still biased the results. Finally, individual cultural, social, religious, and spiritual factors may have influenced the participants' anxiety levels, which would decrease the generalizability of the results of this study to other countries.
Conclusions
The results of this study support that the NSM has the potential to significantly and positively reduce anxiety in patients scheduled for CABG surgery. This model may be easily used in practice as a guide for nurses to provide quality care to patients awaiting surgery. Therefore, the NSM may be a suitable theory to apply in reducing anxiety in patients scheduled for CABG surgery. The results of this study are applicable for nurses, nursing managers, and hospital managers to provide holistic care to patients in hospital and community settings.
Acknowledgments
The results of this research are part of a master's thesis in nursing that was approved by the Isfahan University of Medical Sciences (Grant No. 396838). We express our appreciation to the research deputy, patients, and nursing staff for their cooperation during this study.
Author Contributions
Study conception and design: EA, SB
Data collection: EA
Data analysis and interpretation: EA, SB, AM
Drafting of the article: All authors
Critical revision of the article: FE, AM
References