| Abstract|| |
Non-adherence to prescription is common among hemodialysis (HD) patients and has been associated with significant morbidity. At least 50% of HD patients are believed to be non-adherent to some part of their treatment. We aimed to assess the prevalence of non-adherence to dialysis prescription among 100 chronic HD patients. We explored the relationship between non-adherence on one hand and socioeconomic profile, depression scores and cognitive function on the other hand. The impact of patients' non-adherence on nutritional status, quality of life and dialysis adequacy was also assessed. The mean age of the study group was 50.51 ± 12.0 years. There were 62 females and 38 males in the study. Thirty-six patients (36%) were non-compliant to their dialysis prescription. No significant differences were detected between compliant and non-compliant patients in their education level and employment status. Inter-dialytic weight gain, serum phosphorus and depression scores were significantly higher in non-compliant patients compared with compliant patients, whereas body weight, serum albumin, serum calcium, quality of life scores and nutrition scores were significantly higher in compliant patients (P <0.05). In conclusion, non-adherence is highly prevalent among chronic HD patients and is associated with poor quality of life, depression and malnutrition.
|How to cite this article:|
Ibrahim S, Hossam M, Belal D. Study of non-compliance among chronic hemodialysis patients and its impact on patients' outcomes. Saudi J Kidney Dis Transpl 2015;26:243-9
|How to cite this URL:|
Ibrahim S, Hossam M, Belal D. Study of non-compliance among chronic hemodialysis patients and its impact on patients' outcomes. Saudi J Kidney Dis Transpl [serial online] 2015 [cited 2019 Aug 21];26:243-9. Available from: http://www.sjkdt.org/text.asp?2015/26/2/243/152405
| Introduction|| |
Non-adherence to the prescribed treatment schedule is a common problem in hemodialysis (HD) patients, and is associated with increased morbidity and mortality. , Studies have shown that the prevalence of non-adherence to fluid restriction ranged from 30- 70%. ,,, Also, estimates of non-adherence to the dietary regimen ranged from 2 - 34% of patients for potassium intake and from 19 - 57% for phosphate intake. , Non-adherence to medications is a major concern in HD patients as recent studies have shown that 19 - 99% of patients were non-adherent to their medications. , Non-adherence through skipping dialysis sessions varied from 7 - 32% among chronic HD patients. ,
The aim of the current study was to analyze the prevalence of non-compliance in a group of chronic HD patients and to investigate its causes and consequences. The study focused on analyzing the potential causes of non-compliance, including demographic factors, education, employment, mental function and presence of depression. The impact on dialysis outcomes was assessed in terms of quality of life, dialysis adequacy and nutritional state.
| Patients and Methods|| |
This study was conducted on 100 chronic HD patients at the Nephrology and Dialysis Center, Al Agouza Hospital, during the period from August 2008 to February 2009. All study patients were on 4-h, thrice-weekly HD sessions using low-flux hemophane membrane dialyzers of 1.2 M 2 (Haidylena Medical SAE, Cairo, Egypt). The dialysate flow was 500 mL/ min and the blood flow rate ranged from 270 - 350 mL/min. All patients had functioning arteriovenous fistulae. All patients gave informed consent and the study was approved by the local research and ethics committee. Non-compliance to dialysis therapy was assessed by the following:
- Measuring the inter-dialytic weight gain (IDWG); the patient was considered non-compliant if the IDWG was more than 5% of the dry weight.
- Serum phosphate was more than 7 mg/dL for three successive months.
- Missing one dialysis session per week.
Possible causes of non-compliance that were explored included the following:
- Patients' socioeconomic factors
Patients' demographic and socioeconomic data, including age, gender, marital status, education and employment status, were recorded.
We used the Beck Depression Inventory (BDI) to assess the presence and severity of depression as a possible cause of non-compliance. The BDI is a 21-item, patient-related scale that has been validated for depression assessment in HD patients.  Scores range from 0 - 63 and depression was diagnosed if the BDI score was more than or equal to 15. 
- Cognitive function
Cognitive function of the patients was assessed by using the Blessed Dementia Information Memory-Concentration test. It is a questionnaire standardized to measure cognitive function (maximum score is 36). 
- Nutritional assessment
Nutritional status of the patients was assessed using the Subjective Global Assessment (SGA) questionnaire, on which the patient ranked as well nourished, mild, moderate or severely malnourished. 
- Quality of life assessment
The SF-36 questionnaire was used to assess the Quality of Life (QoL) in the study group.  It measures eight different dimensions of health: Physical function and role limitations related to physical problems, bodily pain, vitality, general health perception, social function, role limitations due to emotional problems and mental health.  An additional one-item measure of self-evaluated change in health status was added.  Scores were assembled using the Likert method for summated ratings and the raw scores transformed into 0 - 100 scales. Higher scores indicate better health. 
The first five scales make up the physical health dimensions and the last five scales form the mental health dimension.  The English version of the SF-36 questionnaire was used and verbally translated into Arabic for two main reasons: (a) there is no published validated Arabic version of the questionnaire and (b) 27% of the study group was illiterate and needed the investigators' assistance to comprehend the questionnaire.
- Laboratory data
Monthly laboratory data of dialysis patients, including serum calcium, phosphorus, albumin, hemoglobin, serum creatinine and blood urea were recorded.
| Statistical Analysis|| |
The results are summarized as mean ± standard deviation (SD). Analysis of variance was used for testing the significance of differences of the values measured between both groups. P-value <0.05 was taken as statistically significant. All analyses were performed using the SPSS/PC+ package (SPSS Inc., Chicago, IL, USA).
| Results|| |
The mean age of the study group was 50.51 ± 12.0 years (range 21 - 72 years). There were 62 females and 38 males. The mean duration on dialysis was 5.6 ± 3.0 years (0.75 - 13 years). The original renal disease was hypertension (28%), unknown (25%), obstructive uropathy (16%), chronic glomerulonephritis (13%), diabetic nephropathy (6%), systemic lupus erythematosus (6%), polycystic kidney disease (2%), reflux nephropathy (2%) and pre-eclampsia (2%).
The mean serum hemoglobin was 9.22 ±1.6 g/dL (range 6.6 - 13.2 g/dL). The mean serum calcium and phosphorus were 8.49 ± 1.0 mg/dL (range 6.1 - 10.6 mg/dL) and 5.89 ± 1.57 mg/dL (range 2.2 - 12.5 mg/dL), respectively. The average urea reduction ratio (URR) was 61.4 ± 9.1% (range 49 - 83%). Six patients were hepatitis B surface antigen (HBs Ag) positive and 55 patients were hepatitis C virus (HCV) antibody positive.
Prevalence of non-compliance
Thirty-six patients were non-compliant to their dialysis prescription. They included 20 females and 16 males, with mean age 49.9 ± 12.7 years (range 21 - 71 years). There were no statically significant differences between complaint and non-compliant patients with regard to age and gender (P ≥ 0.05) [Table 1].
|Table 1: Comparison between compliant and non-compliant groups regarding study parameters.|
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As shown in [Table 1], 76.6% of the compliant patients were married compared with 50% of the non-compliant patients (P <0.05), and 25% of the non-compliant patients were divorced compared with 3.1% of the compliant group( P <0.05). No significant differences were detected between compliant and non-compliant patients in their education level and employment status. IDWG, serum phosphorus and BDI scores were significantly higher in non-compliant compared with compliant patients (P <0.05). On the other hand, body weight, serum calcium, serum albumin, QoL scores and SGA scores were significantly higher in compliant compared with non-compliant patients (P <0.05). Correlation between dialysis adherence and clinical and laboratory parameters among the study group.
There was a significant negative correlation between dialysis compliance and serum phosphorus and BDI (P <0.5). There was a significant positive correlation between dialysis and drug compliance and serum calcium, serum albumin, SF-36 and SGA scores (P <0.05). No significant correlations were detected between dialysis compliance and age, weight, duration on dialysis and URR, Blessed dementia memory test scores, serum hemoglobin and IDWG (P >0.05).
Our study showed that 36% of HD patients were non-compliant to their dialysis and/or drug prescription. Leggat et al have reported that two to more than 50% of HD patients were non-compliant with some part of the HD regimen.  The study showed no significant difference in age between compliant and non-compliant HD patients (P >0.05). Similarly, Bland et al reported a lack of significant differences in compliance among HD patients based on age.  Larsen et al showed that compliance increased with age and that wide variation existed between countries. 
No significant difference was found in gender between compliant and non-compliant HD groups in our study (P >0.05). This result is in agreement with results from Bland et al.  Takki et al reported that male gender constituted 65.2% of the non-compliant study group.  Saran et al reported that non-compliance to HD is more common among males, with a percentage of 59.7% in Euro-DOPPS and 62.4% in Japan.  Also, in our study, there were significantly higher numbers of divorced patients among non-compliant patients compared with the compliant group (P = 0.002). This result is in agreement with a previous study that looked at non-compliance rates among a group of chronic HD patients in Egypt. 
Regarding education level and employment status, our study revealed that 33.3% of non-compliant patients were illiterate and 58.3% were employed; there was no significant difference between compliant and non-compliant groups in this aspect (P >0.05). This result is in agreement with Bland et al who reported that educational level had no significant impact on the compliance of HD patients. Similarly, the cognitive function questionnaire revealed no significant difference between compliant and non-compliant patients.
HD patients are at a higher risk for viral hepatitis infection due to repeated blood transfusions and potential for exposure to infected patients and contaminated equipments.  Our study revealed that 6% of the study patients were HBsAg positive. Anti-HCV antibodies were detected in 55% of the total HD patients. Khodir et al reported a prevalence of 35- 42.2% of anti-HCV antibodies in a group of HD in the Al Gharbiyah Governorate, Egypt.  In 2008, nearly 15% of the population aged 15 - 59 years had antibodies to HCV and an estimated five million Egyptians had chronic HCV infection. 
The amount of IDWG in chronic HD patients is known to correlate with the level of compliance to fluid restriction. Non-compliance in dialysis patients was once defined as an IDWG >1.5 kg.  Our study showed that the weight of compliant patients was statistically higher than that of the non-compliant patients, and that the IDWG was statistically higher among the non-compliant group in comparison with the compliant group (4.69 ± 1.39 kg vs. 3.64 ± 1.0 kg). Denhaerynck et al reported that 42% of HD patients were non-adherent to fluid restriction, with a mean IDWG of 2.48 ± 1.12 kg.  The prevalence of increased IDWG was 34.5% in Japan, 16.8% in the United States and 11% in Euro-DOPPS. 
In ESRD patients, the BDI correlates highly with the diagnostic criteria of depression, QoL, severity of illness and mortality.  In this study, the BDI scores were significantly higher among non-compliant patients compared with the compliant patients (17.28 ± 5.75 and 12.89 ± 6.5, respectively, P <0.05) [Figure 1]. Ibrahim et al reported a high prevalence of depressive symptoms among a group of Egyptian chronic HD patients, with 33.33% having BDI scores more than 15.  Boulware et al reported a prevalence of depression of 19 - 24% in the Choice for Healthy Outcomes in Caring for End-Stage Renal Disease (CHOICE) study. 
|Figure 1: Depression scores in the non-compliant and compliant groups (P < 0.001).|
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Our results showed that non-compliant patients had significantly lower QoL scores compared with compliant patients (50.2 ± 12.0 and 60.9 ± 14.9, respectively, P <0.05). Patients with BDI scores >15 had significantly lower QoL scores (P <0.05). We have previously shown a significant impairment of QoL scores in chronic HD patients. 
The serum phosphorus level was significantly higher among non-compliant compared with compliant patients (6.6 ± 1.93 mg/dL vs. 5.17 ± 1.2 mg/dL, P <0.05). Leggat et al reported that 22% of non-compliant patients had a serum phosphorus level greater than 7.5 mg/dL.  Hyperphosphatemia ≥7.5 mg/dL was present in 15.4% of dialysis patients in the United States, 12.8% in the Euro-DOPPS and 12.1% in Japan. 
Serum albumin is the strongest laboratory predictor of dialysis mortality as it reflects the nutritional status as well as the extent of systemic inflammation.  Serum albumin was significantly higher in the compliant compared with the non-compliant group (P = 0.049). Similarly, SGA scores were significantly higher in the compliant group.
In conclusion, our study revealed a high prevalence of non-compliance among a group of chronic HD patients. Depression scores were higher and QoL scores were significantly impaired among the non-compliant group. Non-compliance was associated with malnutrition, as assessed by serum albumin and subjective global assessment scores.
Conflict of interest: None declared.
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Dr. Salwa Ibrahim
Department of Internal Medicine, Cairo University, Cairo