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Saudi Journal of Kidney Diseases and Transplantation
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ORIGINAL ARTICLE  
Year : 2020  |  Volume : 31  |  Issue : 6  |  Page : 1294-1302
Experiences of stress appraisal in hemodialysis patients: A theory-guided qualitative content analysis


1 Department of Aging Health, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
2 Environmental and Occupational Hazards Control Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
3 Department of School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4 Department of Medical Psychology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
5 Department of Urology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
6 Department of Health Education and Health Promotion, Kerman University of Medical Sciences, Kerman, Iran

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Date of Web Publication29-Jan-2021
 

   Abstract 


Chronic renal failure and prolonged hospitalization for the treatment of renal disease incur immense stress and anxiety in patients. Considering the increased prevalence of renal failure, the present study aimed to explain the experiences of stress assessment in hemodialysis (HD) patients based on the transactional model of Lazarus and Folkman. The data collection method was semi-structured interview with 22 patients from dialysis centers in Tehran. Sampling was purposive and continued until data saturation. Data were analyzed using the directed content analysis method. Data analyzed to the extraction of 80 codes that were classified into two predetermined categories of appraisal structures in the transactional stress model, including primary and secondary appraisal, and also seven subcategories (perceived susceptibility, perceived severity, motivational relevance, casual focus, perceived control over outcoms, perceived control over emotions, and self-efficacy). During this study, 15 sub-subcategories were obtained for the stress appraisal in HD patients. The results showed that the subcategories of perceived susceptibility, perceived severity, and casual focus were the most effective factors in the stress appraisal in HD patients. According to the results, an arrangement should be made so that HD patients can evaluate the stressful conditions properly. patients need help to improve their evaluation in subcategories of motivational relevance, perceived control over outcomes, perceived control over emotion, and self-efficacy. In this regard, one of the best models that can be used to identify the appraisals in HD patients and design appropriate interventions for them is the transactional model.

How to cite this article:
Morowatisharifabad MA, Ghaffari M, Mehrabi Y, Askari J, Zare S, Alizadeh S. Experiences of stress appraisal in hemodialysis patients: A theory-guided qualitative content analysis. Saudi J Kidney Dis Transpl 2020;31:1294-302

How to cite this URL:
Morowatisharifabad MA, Ghaffari M, Mehrabi Y, Askari J, Zare S, Alizadeh S. Experiences of stress appraisal in hemodialysis patients: A theory-guided qualitative content analysis. Saudi J Kidney Dis Transpl [serial online] 2020 [cited 2021 Mar 4];31:1294-302. Available from: https://www.sjkdt.org/text.asp?2020/31/6/1294/308338



   Introduction Top


Chronic renal failure is a condition, in which renal function gradually decreases over time. This disease can be life threatening.[1] Patients with chronic renal disease will have to choose one of the three treatment options: hemodialysis (HD), peritoneal dialysis, and kidney transplantation, so these patients need to deal with different aspects of their life.[2] HD patients are dependent on the dialysis system for survival. Dialysis treatment is a major psychological challenge for these patients due to planning for treatment and dietary constraints.[3] On the other hand, life with dialysis, such as other chronic diseases, is a threat to self-sufficiency due to a significant burden of disease and a change in functional status. These patients are often faced with many problems such as proper occupation, depression from frequent illnesses, fear of death, and impotence.[4],[5] These mental and physical stresses can lead to anxiety, depression, limitation of physical activity, constraint on transport, suicide, and sexual dysfunction. HD patients are therefore threatened with potential losses and lifestyle changes.[6],[7]

Stress is equivalent to stress, anxiety, anxiety, and pressure in the life of an individual.[3] A large number of researchers believe that only a particular change in life causes stress, and this incident causes the same stress for all people.[8] On the other hand, one of the factors that plays an important role in the creation and continuation of emotions is the cognitive factor. Cognition plays an important role in the amount of stress experienced by individuals. Hence, the emotions people experience when facing stressors are heavily influenced by the ways, in which individuals evaluate the stressors in question. Therefore, existence of the stress or lack of it depends on how the stressful situation is evaluated. That’s because some people may be stressed in a stressful situation, while others will only see the same situation as an emotional or challenging one.[9]

One of the models that evaluate the individuals in stressful situations is the transactional model of Lazarus and Folkman. According to this model, all stressful experiences, including chronic diseases, are understood as transactions between individuals and the environment. When the person faces any stressful factor, the first step occurs which is called the primary appraisal, at which the individual determines, internally, the severity of the stressor and whether or not he may be in trouble. At this stage, if the factor is perceived severe or threatening, if the factor has caused damage or loss in the past to the individual or a relative of the individual, the next step occurs, which is the secondary appraisal, in which the individual determines how much control he/she has over the stressor? Based on this understanding of the situation, the individual begins to recognize which control instrument is available to him, but if the stressor is perceived as unrelated or slight threat, then no more stress will be created and there will be no more compatibility.[10]

Appraisals are the most important determinants of coping strategies. Several studies have proven a significant relationship between stress appraisal and various aspects of coping.[11],[12],[13] While much research has been done on HD patients in Iran, the stressors appraisal in these patients has been less studied in Iran. Identifying stressors and appraisal of people in stressful situations through the experiences of people who are directly affected by this phenomenon can be very useful. By identifying individual experiences of the way individuals assess the stress phenomenon and the various aspects of the relationship between this phenomenon and the renal disease, interventions can be designed and implemented with more precise directions and concentrate on experiences. Since each patient can have different experiences in this regard, we tried to identify a qualitative method of evaluation of stresses in HD patients.


   Materials and Methods Top


Design, participants, and research process

In this study, one of the qualitative research methods was used called the directed content analysis. The data collection method was semi-structured interview with 22 patients from dialysis centers in Tehran. Sampling was purposive and continued until data saturation. The duration of the interviews was between 30 and 40 min in the dialysis unit. Study was performed in four months in 2017. Data were analyzed using the directed content analysis (theory guided) method. The inclusion criteria were chronic renal disease, Tehran residence, HD treatment, on the list for transplantation, having a history file at the dialysis center. The interview included the following major questions: I can ask if you are familiar with the word stress? What kind of stress do you have in your life? Do you think these stresses are serious in your life? Have you ever experienced problems due to these stresses in your life? Have you blamed yourself for your stress? Have you been able to cope with your stress? These questions allowed participants to express their views and experiences as fully as possible. Following that, guiding questions were raised according to the contributor’s response: Can you explain more? What do you mean, why and how? Can you give an example? These questions were also used to address all aspects of the issue.

During the interviews, an arrangement was made to not only make the participants trust the interviewer but also to ensure that the participants were not inspired some specific responses.

Data accuracy and robustness

In this research, we tried to use the four criteria for the reliability of the qualitative research presented by Lincoln and Guba. To obtain the credibility, a time-fusion technique was used so that the sampling was carried out at three stages in the morning, noon, and afternoon and the researcher tried to devote a lot of time to collect data, to participate for long and make a persistent observation. In order to ensure data dependability, the peer review method was used, such that the results of the research were made available to experts, so they can express their complementary or critical opinions about what the researcher knew. To improve the confirmability, the researcher tried to avoid involving in the collecting and analyzing the data. Furthermore, to increase the transferability of the results to similar conditions and groups, the participants were selected from a number of health centers with the maximum diversity.[14]

Data analysis

Data analysis was performed according to the steps proposed by Graneheim and Lundman.[15] During the research, all conversations were recorded, transcribed, and analyzed. Immediately after each session, the interview was played several times, transcribed and broken into the smallest meaningful units (code). The codes were classified into two categories (primary appraisal and secondary appraisal), 7 subcategories (perceived susceptibility, perceived severity, motivational relevance, casual focus, perceived control over outcoms, perceived control over emotions, and self-efficacy) and 15 sub-subcategories.

At the beginning of the research, permission was obtained from the Ethics Committee the code of ethics R.SSU.SPH.REC.1397.012 and the relevant references were taken from Iran. Before the study, the participants were told about the study objectives, were invited to participate in the research and received informed consent. The interview time was set at the request of the participants and in coordination with them. During the study, the confidentiality of information, the right to withdraw from the study at any time, and the right to request transcription of interviews were considered.


   Results Top


The participants in this study were 22 HD patients with an average age of 54.7 ± 6.5, whose characteristics are presented in [Table 1]. According to the directed content analysis, 117 primary codes were extracted. After holding numerous meetings with the research team and removing or integrating phrases with the same concept and close phrases, 80 codes remained which were classified into two categories of predetermined structures including two categories (primary appraisal and secondary appraisal), 7 subcategories, and 15 sub-subcategories (sensitivity to injections and their complications, sensitivity to the function of the dialysis system, sensitivity to the environment and staff of the dialysis center, mental complications due to stress, physical complications due to stress, disappointment of solving the stressful situation, high motivation to overcome stressful situations, self-blame for creating stressful conditions, the role of external factors (poverty, family and other patients) in creating stressful conditions, low control on the outcomes of stress, low emotional control in stressful situations, controllability of emotions in stressful situations, ability to overcome the stress by identification with other patients, ability to solve stressful situations based on one’s on abilities, and inability to solve stressful situations due to their dominance on the individual). An example of coding and positioning themes in the categories is given in [Table 2].
Table 1: Characteristics of participants.

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Table 2: Examples of coding the hemodialysis patient interviews and positioning of themes in the transactional model of Lazarus and Fulkman.

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Primary appraisal

Perceived susceptibility: It was observed in patients including three sub-subcategories: sensitivity to injections and its complications, sensitivity to dialysis function, and sensitivity to the environment and staff of the dialysis center. Most renal patients were sensitive to complications from injections or complications of their illnesses; i.e., according to their experiences with the stressful situations of renal disease, they saw themselves at risk from these stressors. Some were even sensitive to the proper functioning of the dialysis equipments and the proper disposal of creatine and urea from blood. Most patients expressed fear and concern about posttransplant complications, and felt threatened by loss of family support for continued treatment and fear of aging and disability. A 57-year-old female described her experience as: “I’m worried every time they are going to connect me to the dialysis equipments. I’m worried that my vessel may be torn”. A 53-year-old male participant said: “This equipment is an old one, a 2005 model. Now it’s 2017. In all countries, these equipments are out of date. The equipment is not tasked with lowering the water level in my body; it is tasked with lowering the poisons in my body, that is, creatine. When they connect me to the equipment, the urea level of my blood is on 100; afterward, it is on 100 again. There is no difference. For example, you see that equipment right there? Last time I was connected to that equipment. I was unhappy until last night.” A 55-year-old male said: “Sometimes you like the environment and the staff. With all the difficulties, you get along the environment and your illness, because you like it. However, when the environment is not desirable, then there are two dilemmas, the environment and the illness”.

Perceived severity: It includes two sub-subcategories of physical complications due to stress, and psychological and emotional complications, again due to stress. Most patients considered stressors to be serious and they were very worried about the consequences to such an extent that these stressors increased their blood pressure in some of them, and others were affected by the stressors such that they did not have the ability to do their job. These stressors had a serious and significant impact on their lives. A number of patients reported that stressors had an unpleasant feeling for them, both physically and emotionally, saying that these stressors may even affect the successful transplantation for all of them. A 54-year-old female said: “When I think about the end of it all, I get sick, restless, and clumsy, my blood pressure goes up and I feel nausea”. A 43-year-old male said: “The illness had a huge impact on me. When I think about it, sometimes I cannot sleep at night.”

Motivational relevance: It includes two sub-subcategories of disappointment and lack of motivation for solving stressful situations and high motivation to overcome the stressful situation. A large number of patients, based on their own experiences, stated that they had little incentive to resolve their stress-related complications because they believed they could not overcome these stressors. In some cases, individuals had varied motivations to resolve the stressors resulting from their illness such that some had a great incentive to resolve their stressors, while others were reluctant and disappointed. A 57-year-old female participant said: “It is an insolvable problem. I’m really frustrated due to the illness. I get board and disappointed when I’m under the stress of the illness”. A 60-year-old woman said: “I always try to overcome my stresses. I’m always looking forward to solutions as far as I can.”

Casual focus: It consists of two sub-subcategories: Blaming oneself in creating stressful conditions and the role of external factors (poverty, family, and other patients) in creating such conditions. Some criticized themselves for not pursuing renal problems in the past and also for the creation of current stressors resulting from dialysis. One 53-year-old man said: “Well, I blame myself for these stresses, if I paid enough attention to my renal problems in the past, I wouldn’t have needed dialysis now, I’m very unhappy with myself’. A 55-year-old man said: “I have nothing to do with anyone. Usually other patients would stress me. They say somebody they know made dialysis and his situations went very wrong, etc. I do not talk with them so much.”

Secondary appraisal: If a person considers the primary appraisal as stressful or threatening, and something that has gave him a loss or damage, the next step occurs, which is the secondary appraisal, in which the individual determines how much control he/she has over the stressor? This stage includes perceived control over outcomes, perceived control over emotions, and self-efficacy.

Perceived control over the outcomes: All patients in the study agreed that they were not able to control the outcomes of illness-related stresses. A 57-year-old woman said: “This is a disease over which the patient has no control; so we have more and more stress every day, because we can do nothing about it.”

Perceived control over emotions: It includes two sub-subcategories of low control over emotions in stressful situations and the controllability of emotions in stressful situations. Some individuals in the study have asserted that, in many cases, their control over their emotions is very limited in the face of stressors, and they cannot control their emotions from stressors due to their illness. Lack of skills to control emotions was one of the problems most patients complained of.

Some patients were also able to control their emotions when confronted with stressful conditions by religious reliefs. A 57-year-old woman said: “I think that when I’m stressed, I cannot control myself at all, I’m angry and aggressive, or I may be screaming”. A 55-year-old man said: “I am the kind of man who is totally unhappy under stressful conditions. I get anxiety all over my body. Anyone can clearly see that I’m pale only by looking at me.” A 43-year-old man said: “In stressful conditions, something that makes me calm is religious beliefs. When I get stressed due to anything, I say my prayers. That makes me 80-90% more relaxed.”

Self-efficacy: It includes three sub-sub-categories: ability to overcome the stress by identification with other patients, ability to solve stressful situations based on one’s on abilities, and inability to solve stressful situations. Lacking skills to deal with the stress of dialysis and strategies to deal with its complications has led some patients to feel that they have low self-efficacy to deal with stressors. Meanwhile a number of patients also stated that they were able to cope with stressors around them, provided that other environmental conditions were appropriate. Others also said they were able to overcome the stresses of their illness, by identification with other patients. A 36-year-old man said: ‘Well, I can usually control most of my stresses. When we come here (dialysis center), we talk together, we express our sympathy. When we see that there are many with the same problem, we get calmer.” A 40-year-old woman said: “I think you can overcome the stress if you are truly religious. You should believe in it 100%. There are many issues but human being is a complex creature, and he can solve the problems if he can overcome himself.” A 55-year-old man said: “A renal patient cannot really control his stress. It’s a disease that will not be cured. We should get along with it. We can do nothing about it.”


   Discussion Top


The findings indicate that the experiences of dialysis patients in relation to evaluations on stressors can be explained according to the transactional model of Lazarus and Folkman under the influence of constructs such as primary appraisal (perceived susceptibility, perceived severity, motivational relevance, and Casual focus) and secondary appraisal (perceived control over outcomes, perceived control over emotions and self-efficacy).

Primary appraisal: In the present study, most of the patients considered themselves sensitive to stress-related complications and their main concern was the complications of dialysis. These patients accept HD to solve the acute and threatening problem of chronic renal disease. However, a high stress is observed in these patients over the ambiguous future renal transplants. Since renal disease is a serious disease, the feeling of being threatened incurred disturbance, depression, and stress in patients. In various studies, the relationship between perceived stress serverity and emotional coping has been proven, like the study of Masoudnia et al[15] and Folkman et al[16] Those who feel that they cannot control their stressful conditions, or they do not have the ability to solve stressful conditions, these patients are more inclined to use emotional-focused coping strategies. In terms of motivational relevance, lots of patients had a low motivation to resolve a stressful situation. Perhaps one of the reasons for this is that due to the severity of the chronic disease, all people believed that they could not control many of the complications of the disease, thereby they had a low motivation in the face of stressors. The stress of the disease affects the patients differently so that those who considered themselves sensitive to stressful conditions and thought it had serious effects, had a higher motivation to solve the stress from their environment, and those with lower motivational relevance or a lower perception, had a lower motivation to solve the stress. Smith et al stated in their research that the primary appraisal is related to the motivational and causative factors of stress, during which a person suffers from certain mental health problems or pressures. Moreover, if they become more severe, they put the health of the individual at risk.[17]

Casual focus: Some patients blamed themselves for the emergence of stressful situations; they felt more guilt and depression than worrying. The findings of the present study are consistent with the study by Smith et al, who also states that if one considers himself to be in charge of stress, he may feel guilt and depression more than worrying.[18]

Secondary appraisal: Here we have the sub-categories of perceived control over outcomes, perceived control over emotions, and self-efficacy. In the present study, most patients thought that their perceived control over outcomes is very weak when they were exposed to stressful conditions. They stated that, when they were exposed to disease-related stressors, they had little control over the outcomes of their illness, and this cause them more stress. Furthermore, they felt more relaxed when they believed they could control the outcomes of the stressors. In the case of perceived control over emotions, most patients also felt that they could control their emotions when faced with stressors. However, in most cases when facing stressors from dialysis, they were sensitive and mostly had severe emotional reactions, especially at the early stages of the disease. However, they could adapt to these conditions and control their emotions in the context of disease-related stresses. In various studies, there is a close relationship between the perceived control of a disease and its psychological adaptation. Specifically, this is true about the study by Norton et al[19] on cancer patients, or the study by Moser et al[20] on cardiac patients. Most of the patients under study also had low self-efficacy to deal with stressful situations and believed that they were not able to cope with this volume of stresses. The role of self-efficacy in the selection and preservation of health behaviors was confirmed by several studies. Sabzmakan et al[21] said during their research that the subjects were highly confident in their ability to the preserve dieting. In the study by Pawlak et al, subjects also reported high self-efficacy for buying and eating healthy foods. They considered the role of self-efficacy to be very effective in improving the diet.[22] The difference between these and the present study is due to the difference in the type of disease of the subjects under study.


   Conclusion Top


The results of this study indicate that most chronic renal patients experience a lot of stresses due to HD and their illness, which has caused a lot of problems in their everyday lives, in such a way that they cannot live a normal life anymore. Patients expressed different experiences in assessing stressful conditions. Therefore, it is required that special attention is paid to the main stressors in their lives and provide solutions for the proper assessment of these stressors. Family, community, medical and therapeutic staff, and all those who are connected with HD patients should avoid the stress, especially the stresses that can be controlled by these people. However, if a person is stressed for any reason, the patients’ abilities and facilities should be improved, so that the person would be able to properly (secondary) appraise the situation. Meanwhile, mass media, families, and the dialysis environment are of particular importance. In this regard, one of the best models that can be used to identify the assessments in HD patients and design appropriate interventions for them is the transactional model of Lazarus and Folkman.

One of the limitations of the present research is the statistical society that included hemodialized patients, which certainly caused limitations on the generalization of the findings, interpretations, and causative citations of the variables under study. This study was limited due to the conditions of the patients under study such as failure to generalize the findings to other types of diseases. There were also few studies in evaluating patients in stressful conditions that prevent comparison of the results of this study with other studies.

Conflict of interest: None declared.



 
   References Top

1.
Parvan K AR, Hosseini FA, Abdollahzadeh F, Ghojazadeh M, Jasemi M. Coping methods to stress among patients on hemodialysis and peritoneal dialysis. Saudi J Kidney Dis Transpl 2015;26:255-62.  Back to cited text no. 1
[PUBMED]  [Full text]  
2.
Juliana MP. Stress and coping among indian haemodialysis patients. IntJ Pharm Biol Sci 2015;5:18-23.  Back to cited text no. 2
    
3.
Shinde MP. Stressors and the coping strategies among patients undergoing hemodialysis. Int J Sci Res 2014;3:266-79.  Back to cited text no. 3
    
4.
Udaya TA. Level of stress and coping abilities in patients onchronic hemodialysis and peritoneal dialysis. Indian J Nephrol 2003;13:89-91.  Back to cited text no. 4
    
5.
Rojas JN. Stress and coping mechanisms among hemodialysis patients in the gulf and neighboring countries: A systematic review. Int J Adv Res Technol 2017;6:36-40.  Back to cited text no. 5
    
6.
Gurkan A, Pakyuz SÇ, Demir T. Stress coping strategies in hemodialysis and kidney transplant patients. Transplant Proc 2015;47:1392-7.  Back to cited text no. 6
    
7.
Shirazi M, Azim KH, Khosravani E. Effectiveness of psychological rehabilitation, using Dohsa-Hou, on hemodialysis patients’ depression, anxiety, and stress in Zahdan city. J Birjand Univ Med Sci 2016;23:130-40.  Back to cited text no. 7
    
8.
Mosavi Nasab SM, Taghavi M. The effect of stress appraisal and conflict strategies on mental health. Hormozgan Med J 2006;11:83-90.  Back to cited text no. 8
    
9.
Lazarus RL. Progress on a cognitive-motivational-relational theory of emotion. Am Psychol 1991;46:819-34.  Back to cited text no. 9
    
10.
Safari M, SHojaei-zade D, GHofrani F, Hedarnya A, Pakpor A. Health education and promotion. Knowledge 2nd ed. Tehran: Sobhan; 2012.  Back to cited text no. 10
    
11.
Folkman S, Lazarus RS. An analysis of coping in a middleaged community sample. J Health Soc Behav 1980;21:219-39.  Back to cited text no. 11
    
12.
Holt NL, Dunn JG. Longitudinal idiographic analysis of appraisal and coping responses in sport. Psychol Sport Exe 2004;5:213-22.  Back to cited text no. 12
    
13.
Lengua LJ, Long AC. The role of emotionality and self-regulation in the appraisal-coping process: Tests of direct and moderating effects. J Appl Dev Psychol 2002;23:471-93.  Back to cited text no. 13
    
14.
Streubert H, Carpenter D. Qualitative Research in Nursing: Advancing the Humanistic Perspective. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999.  Back to cited text no. 14
    
15.
Masoudnia E. Perceived severity of stress and coping strategies with stress. Contemp Psychol 2010;4:71-80.  Back to cited text no. 15
    
16.
Folkman S, Moskowits JT. Positive affect and the other side of coping. Am Psychol 2000;55:647-54.  Back to cited text no. 16
    
17.
Smith CA. Appraisal components, core relational themes, and the emotions. Cognit Emot 1993;7:233-69.  Back to cited text no. 17
    
18.
Smith CA, Haynes KN, Lazarus RS, Pope LK. In search of the ‘Hot’ cognitions: attributions, appraisals, and their relation to emotion. J Personal Soc Psychol 1993;65:916-29.  Back to cited text no. 18
    
19.
Norton TR, Manne SL, Rubin S, et al. Ovarian cancer patients’ psychological distress: The role of physical impairment, perceived unsupportive family and friend behaviors, perceived control, and self-esteem. Health Psychol 2005;24:143-52.  Back to cited text no. 19
    
20.
Moser DK, Riegel B, Mckinley SD, Doering LV, An K, Sheahan S. Impact of anxiety and perceived control on in-hospital complications after acute myocardial infarction. Psychosom Med 2007;69:10-6.  Back to cited text no. 20
    
21.
Sabzmakan L, Mazloomy Mahmoodabad SS, et al. Patient experiences with cardiovascular risk factors and health workers from nutritional behavior determinants: An analysis of content-driven quality. Iran J Endocrinol Metab 2013;15:292-302.  Back to cited text no. 21
    
22.
Pawlak R, Colby S. Benefits, barriers, self-efficacy and knowledge regarding healthy foods; perception of African Americans living in eastern North Carolina. Nutr Res Pract 2009;3:56-63.  Back to cited text no. 22
    

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Correspondence Address:
Somayeh Alizadeh
Department of Health Education and Health Promotion, Kerman University of Medical Sciences, Kerman
Iran
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DOI: 10.4103/1319-2442.308338

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