Correlation between quality of life and adherence to treatment in hemodialysis patients

1School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2Department of Nursing, Faculty of Nursing and Midwifery, Zabol University of Medical Sciences, Zabol, Iran 3Department of Nursing Management, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran 4Department of Medical–Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran 5Department of Pediatrics, Faculty of Medicine, Zabol University of Medical Sciences, Zabol, Iran 6Community Nursing Research Center, Zahedan University of Medical Sciences, Zahedan, Iran


Introduction
The end-stage renal disease characterized by progressive and irreversible degeneration of kidney functioning (1) causes accumulation of toxins, the presence of uremic syndrome and considerable complications in the body.Although recent advancements in medical sciences and the possibility of kidney transplant have opened new horizons to these patients, some of these patients cannot receive kidney transplant (2) and require hemodialysis to save their lives (3).The data of US renal information system indicated that about 90% of the patients affected with this disease undergo hemodialysis.The hemodialysis patients' data increase in Iran by %15 annually (4).Hemodialysis is not able to treat the disorder and compensate for all the impaired metabolic or endocrine functions of the kidney (2).Additionally, it is associated with the incidence of acute complications (hypotension and/or muscular spasm) and chronic disorders (anemia and viral hepatitis B and C) (5).In addition, the hemodialysis patients often suffer from feelings of having no freedom, dependence on relatives, impaired familial and social life, and reduced or no income (6).Fatigue, lethargy, disability, diminished sexual desire, and even major depression associated with time-consuming and difficult hemodialysis can decrease patients' feeling of well-being (7) and disturb their quality of life (6).It can also cause changes in life style, health status and individual's roles (8).These patients are exposed to numerous physical, mental, and social stressors (9,10).Quality of life is an all-inclusive concept involving various aspects of life such as financial status, occupation, love, religion, and also the physical, mental, and social health.Perception of their status in life with respect to the cultural context and value systems with which they live considering their goals, expectations, standards and concerns (11).Studies conducted in this field indicate alarmingly the weak quality of life in these patients compared to the healthy community (12)(13)(14).Paying attention to the life quality of these patients is important since according to some evidence, it is related to medical outcomes such as reduced patient hospitalization and decreased mortality rate related to hospitalization (15,16).One of the problems reported about hemodialysis patients is the deficiency in their adherence to treatment.This term refers to all patient behaviors (diet, fluids and drug administration) aimed at fulfilling the recommendations given by health care-givers (17,18).Lack of compliance with diet is common among the hemodialysis patients so that about 25%-86% of these patients do not comply with their diet (19).Compliance with diet, drug program, and fluid intake constraints are of utmost importance and can play a significant role in improving health level and feeling of well-being in hemodialysis patients (20,21).Any shortcoming in adherence to treatment in these patients often leads to extra para-clinical tests, modified treatment plan, modified prescribed medicines, increased proportion of hospitalization and increased medical costs (22,23).Given the importance of adherence to treatment in hemodialysis patients, several studies have been carried out in various countries.García-Llana et al (24,25) in Spain and Oliveria et al (26) in Brazil investigated quality of life and adherence to treatment of these patients.However, a review of the related studies in Iran demonstrated that no study has comprehensively and simultaneously surveyed the life quality and adherence to treatment in these patients despite the important role of the effect of adherence to treatment on quality of life in these patients.
Of course, the status quality of life and adherence to treatment have been examined in numerous studies using different instruments or laboratory indices separately.For instance, Soleimanzadeh et al (27) explored the life quality of hemodialysis patients, however, they did not investigate their adherence to treatment.Fouladi et al (28) also studied the prediction of quality of life of hemodialysis patients on the basis of positive psychological variables and mental pathology and traumatology without considering adherence to treatment.Consequently, the present study was carried out considering the impact of adherence to treatment on the quality of life of hemodialysis patients and the necessity of its investigation in a single comprehensive study.

Objectives
This study sought to determine the quality of life in hemodialysis patients who presented to hemodialysis facilities affiliated to Shahid Beheshti University of Medical Sciences in Tehran on the basis of adherence to treatment.

Study design
This study is a correlational descriptive-analytic investigation.

Sampling and procedures
The study population included hemodialysis patients in five hospitals affiliated to Shahid Beheshti University of Medical Sciences, Tehran, during 2017.The data were gathered during 8 months from October 2016 to May 2017 in Tehran, Iran.Given that 5 to 10 samples are required for each variable in SEM studies (29), 200 samples were determined as sample volume in this study.The proportion of samples in each hospital was determined with respect to the volume of hemodialysis patients in that center.Availability sampling method was applied to select the patients who observed the inclusion criteria.The inclusion criteria were; patients with chronic renal failure, being a native speaker of Persian language, voluntary participation in the study, and undergoing hemodialysis during the recent week or the recent year.The exclusion criteria were; auditory or verbal/oral problems in patients and lack of inclination for participation.

Ethical issues
The research followed the tenets of the Declaration of Helsinki.Sampling was done after obtaining approval of Committee of Ethics in Research at Shahid Beheshti University of Medical Sciences under ethics code; IR.SBMU.PHNM.1394.198and getting written permission from the university authorities.The study units were oriented with the goals and procedures of the study and method of completing the questionnaires and were assured of anonymity and patient information confidentiality.Then, informed written consent was obtained from each patient and they were assured that at the time of publishing the results of the study, their personal information will remain confidential.They were told that they could leave the study voluntarily at any stage.They were also informed that leaving the study will not affect the course of their treatment and care.Briefly, this study observed all ethical issues in human research.

Study questionnaires
The data collection instruments included: 1. Demographic information questionnaire including variables such as age, gender, education level, marital status, occupational status and history of hemodialysis.2. Kidney Disease Quality of Life Questionnaire (KDQOL) the validity and reliability of which were established by Pakpour et al (30).This inventory includes eight subscales of kidney disease patients.The Health-Related Quality Of Life Questionnaire is the shortened form of 36-item first version which consists of eight categories; physical performance (10 items), role limitation caused by physical problems (4 items), role limitations induced by emotional problems (3 items), social performance (2 items), feeling of emotional well-being (5 items), pain (2 items), lethargy (fatigue) and energy (4 items) and perceived general health (5 items).It contains a general item on health.The results obtained from this instrument were finally classified in two sections of summary of physical and mental health status.The second part of the tool is specific to hemodialysis patients and consists of the subscales of signs and problems including muscular and chest pain (12 items), the effect of renal disease on life (8 items), the burden of responsibility of renal disease (4 items), occupational status (2 items), cognitive performance (3 items), quality of social interaction (3 items), sexual performance (2 items), sleeping (4 items), social support (2 items), encouragement by hemodialysis ward personnel (2 items) and patient satisfaction (1 item).This instrument is completed by self-reporting.The items in this tool are responded by direct responses ranging from never = 0 to always = 100 (items #3, 9, 10, 11, 12, 17, 19, 21, 22, 23), or with reverse responses ranging from always = 0 to never = 100 (items #1, 2, 4-8, 13-16, 18, 20, 24) or on a vector with a spectrum of 0-100 (items #13, 18).Scoring the items with reverse responses (low scores reflected favorable status) was done by devoting 100 points to "always" and 0 point to "never".The range of scores of any items and scales were set between 0-100 points.Higher scores in any of the items indicated better quality of life.The validity and reliability coefficients of this tool were calculated as 0.77 and 0.83, respectively.

The standard questionnaire of adherence to treatment in end-stage chronic renal failure patients (ESRD-AQ)
It consists of 5 main sections with 46 items; the first section includes general information (5 items), the second section, acceptance of treatment by hemodialysis (14 items), the third section, acceptance of drug therapy (9 items), the fourth section, fluid intake constraints (10 items), and the fifth section, the recommended food diet (8 items).The total score of adherence to treatment is estimated as the sum of the points of these 5 sections.The minimum and maximum scores of the questionnaire were predicted as 0 and 1200 points, respectively.A higher score on this tool indicated better adherence to treatment.The scores were finally classified on the basis of Likert scale.As in Kim and colleagues' study, an SD higher and lower than the mean of total adherence to treatment and its categories was rendered as moderate adherence to treatment, scores lower than that as weak adherence to treatment, and scores higher than that as good adherence to treatment.The validity and reliability coefficients of this instrument have been reported by Kim et al (31) as Cronbach's α of r = 0.75 and test-retest correlation coefficient of r = 0.83.The validity and reliability coefficients of this inventory were estimated in this study as r = 0.98 and r = 0.85, respectively.

Statistical analysis
The items in each section of the questionnaire were responded by the patients themselves using self-reporting technique during the first 30 minutes after beginning of hemodialysis to stabilize the patient's status and create almost equal conditions for responding.The completion of KDQOL required almost 30 mines while the ESRD-AQ was completed in almost 20 minutes.The gathered data were analyzed with SPSS version 18 using descriptive statistics of frequency, mean ± SD and also inferential statistics including Kolmogorov-Smirnov test to determine normal data distribution, student's t test, oneway ANOVA.In this study P value of less than 0.05 was considered significant.

Sample characteristics
A total of 200 hemodialysis patients participated in this study.Fifty percent of the samples were male.Most of the respondents (23%) were 51-60 years old.Other demographic information of the samples is given in Table 1.As can be observed in Table 1, the hemodialysis time of most participants (48%) of the study was 6-10 months and 64% of them were married.Furthermore, 26.5% of the patients had primary school education and 57% were employed.Table 2 also demonstrates that the mean total score of quality of life of the patients was 46.43 (25.47%) and the mean of total score of adherence to treatment was 613.84 (29.01%) (Table 3).There was no significant correlation between demographic variables and quality of life in these patients (Table 4) (P > 0.05).Our results (Table 5) further indicated, no significant correlation between demographic variables (education level, occupational status, and hemodialysis time) and adherence to treatment (determination coefficient = 0.04).Moreover, our findings on adherence to treatment and quality of life in hemodialysis patients suggested that adherence to treatment had a significant impact on quality of life (P < 0.05) (Table 6).In other words, adherence to treatment can predict the quality of life in hemodialysis patients.

Discussion
Our findings showed that the mean total score of quality of life in hemodialysis patients was 46.43 (25.47%) and the mean total score of adherence to treatment was 613.84 (29.01%).According to these results, the quality of life in these hemodialysis patients was almost favorable.Rodrigues Fructuoso et al (32) stated in their study that the mean total score of quality of life in hemodialysis patients was less than the normal score and the quality of life these patients was low.Nonetheless, Mazairac el al (33) in their study on 570 hemodialysis patients demonstrated that the quality of life's their patients has been within   normal limits.Additionally, Tanita et al (34) concluded in their study that the quality of life in hemodialysis patients was relatively high.Likewise, in the study by AL-Jumaih et al (13) conducted in Saudi Arabia, the mean total score of quality of life in hemodialysis patients was high and on the whole, the patients enjoyed appropriate quality of life in all features of physical and mental health and aspects of renal disease.These findings are consistent with our results.The status of adherence to treatment was at the moderate level for most patients.In another study carried out in Italy, it was observed that the rate of adherence to treatment was very weak in most patients (35).Similarly, in another study, the total rate of adherence to treatment in hemodialysis patients was at the moderate level.This is consistent with our results (36).Regression analysis showed that, a significant correlation between total score of quality of life and rate of adherence to treatment (P < 0.01) was detected, indicating that adherence to treatment affects quality of life significantly.In the other words, adherence to treatment can predict quality of life in patients undergoing hemodialysis.García-Llana et al (25) indicated that, a positive significant correlation between adherence to treatment, quality of life, physical performance, and the range of physical pain.Nabolsi et al (37) reported a positive significant correlation between quality of life and adherence to diet therapy.This is consistent with our

Conclusion
Lack of adherence to treatment is a common problem among hemodialysis patients leading to progress or deterioration of the disease, increased hospital stay and inappropriate response of these patients to hemodialysis.Our results indicated that most patients under study showed adherence to treatment which affected their quality of life significantly.Therefore, identifying the factors that influence the patients' lack of adherence to treatment can be applied to foster the quality of life in these patients.

Limitations of the study
One of the limitations of this study was that the questionnaires were completed for some patients during dialysis and that the questionnaires were long and exhausting.It is mandatory to consider the conditions and individuals' characteristics when we want to resolve problems and improve the status of adherence to treatment in patients.Nurses can play a significant role in enhancing adherence to treatment in hemodialysis patients through establishing strong supportive relations with patients.Nurses can use the findings of this study to help to promote adherence to treatment in hemodialysis patients.A limitation of our study was small proportion of patients.We suggest multi-centric investigations on this aspect of the renal disease.

Table 1 .
The frequency distribution of the demographic characteristics of the participant

Table 2 .
The mean and standard deviation of important dimensions of quality of life

Table 3 .
The mean and standard deviation of important dimensions of adherence to treatment

Table 4 .
Linear regression model of the effect of demographic variables on the quality of life score

Table 5 .
(40)ar regression model of the effect of demographic variables on the quality of life score with adherence to treatment.On the other hand, the results of this study demonstrated that none of the demographic variables exerted a significant effect on the score of quality of life.García-Llana et al(25)reported a significant correlation only between age and quality of life in hemodialysis patients.In the study by Oliveria et al(40), females obtained a smaller score of physical role compared to males.