| Abstract|| |
Chronic kidney disease (CKD) patients who reach end-stage renal disease (ESRD) require early nephrology referral and appropriate vascular access. Arteriovenous fistula (AVF) is the preferred access for hemodialysis (HD). Referral to nephrology of CKD patients starting HD in Jordan and its impact on AVF utilization is unknown. Patients on in-center HD in a large Jordan Ministry of Health dialysis unit were interviewed, and medical records reviewed to assess prior nephrology care and AVF use. Of 104 total patients, 93 met the inclusion criteria. The mean age was 50 ± 16 years, with 44% being females. The average body mass index was 25 ± 5. The cause of ESRD was diabetes mellitus in 28 (30%), hypertension in 28 (30%), and polycystic kidney disease in three (3%). Type of HD access at the initiation of dialysis was central venous catheter (CVC) in 80 (86%) and AVF in 12 (13%). Of the overall group, 50 (54%) were seen by nephrology before initiating dialysis, and of these, 39 patients (78%) were seen >1 year before HD initiation. Of the patients who initiated dialysis with a CVC, 38 (48%) had received prior nephrology care. All 12 patients who initiated dialysis with AVF had received prior nephrology care. Of the 50 patients who received nephrology care before dialysis initiation, 12 patients (24%) had started dialysis with an AVF; in patients without prior nephrology care, all were started with a CVC. In conclusion, our study suggests that a large percentage did not have nephrology care before initiating dialysis. The ones who were seen by nephrology before dialysis were significantly more likely to initiate dialysis using an AVF. A national focus on improving nephrology referral in advanced CKD may allow better utilization of AVF as the method of access at dialysis initiation.
|How to cite this article:|
Hamadah AM, Gharaibeh K. Predialysis nephrology care and its impact on initial vascular access type in hemodialysis patients in Jordan. Saudi J Kidney Dis Transpl 2019;30:1103-10
|How to cite this URL:|
Hamadah AM, Gharaibeh K. Predialysis nephrology care and its impact on initial vascular access type in hemodialysis patients in Jordan. Saudi J Kidney Dis Transpl [serial online] 2019 [cited 2020 Aug 11];30:1103-10. Available from: http://www.sjkdt.org/text.asp?2019/30/5/1103/270266
| Introduction|| |
Patients with chronic kidney disease (CKD) who reach dialysis-requiring end-stage renal disease (ESRD) require close nephrology care and appropriate vascular access. Arteriovenous fistula (AVF) has been recommended as the access method of choice for patients who choose to undergo hemodialysis (HD) when ESRD is reached.,,, Compared to arteriovenous graft (AVG) and central venous catheters (CVC), AVF has been associated with lower risk of infection and decreased mortality, among other advantages.,,,,, However, the number of patients starting HD with CVC or AVG remains high. The fistula first initiative was a quality improvement initiative introduced by the United States Center for Medicare and Medicaid in 2003 as the National Access Improvement Initiative to increase utilization of AVF. The initial goal was to increase the prevalence of AVF use to 40% which was later increased to 65% as a projected target goal by 2009. This initiative led to an actual increased utilization of AVF with increase in prevalent use from 33% in all HD patients in 2003 to 62.7% by mid-2016., However, utilization of CVC remains high, especially at initiation of dialysis which, in 2015, represented 80% of access used. Many barriers to the timely creation of AVF have been identified. These include system-based, provider-related, or issues pertaining to patient preferences or perception.  One of the modifiable aspects associated with increased AVF utilization at initiation of dialysis is early predialysis referral to nephrology. From 2005 to 2013, the percentage of CKD patients receiving care from a nephrologist at least 12 months before the start of renal replacement therapy (RRT) increased from 25% to 34%, but this figure remains low. The US Office of Disease Prevention and Health Promotion’s Healthy People 2020 initiative has set an objective to “increase the proportion of CKD patients receiving care from a nephrologist at least 12 months before the start of RRT” and “increase the proportion of adult HD patients who use AVFs or have a maturing fistula as the primary mode of vascular access at the start of RRT.”
Approximately 5350 Jordanian patients were on dialysis in 2016 according to the Report by the Ministry of Health which is published annually. This is approximately 754 per million of the total Jordanian population in 2016. In this report, 98% of the patients were reported to be on HD and only 2% were on peritoneal dialysis (PD). Although this report details important aspects pertaining to the dialysis population in Jordan, it does not address issues related to the type of access, access utilization, and predialysis nephrology care. To our knowledge, there has not been a formal assessment of predialysis nephrology care and its effect on AVF utilization in Jordan. In this study, we aim to assess the rate of predialysis nephrology care in Jordanian HD patients and assess its impact on vascular access type at dialysis initiation. This information is to be used to improve the fistula creation and utilization process and to also be used in future studies focusing on aspects of change in utilizing AVF in HD patients in Jordan.
| Materials and Methods|| |
Study design and setting
This is a cross-sectional study assessing predialysis care and referral to nephrology specialty clinic among HD patients in Jordan and its impact on type of HD access at the time of initiation of HD. This study was conducted at Prince Hamza Hospital which is a part of the Ministry of Health Services in Amman, Jordan. This study was conducted from May to August 2018. It was done at the hospital outpatient HD unit which is considered one of the largest Ministry of Health dialysis units in Jordan as per the number of patients who undergo HD weekly.
Adult patients, with the diagnosis of ESRD, undergoing in-center HD on a regular schedule of Tuesday-Thursday-Sunday or Monday-Wednesday-Saturday were included in this study. Patients who were on acute dialysis, those with mental illness that precludes ability to participate and fully consent, in addition to those who declined to participate or were unavailable at the time of the study, were excluded. The study was approved by the Institutional Review Boards at both the Hashemite University and Prince Hamzah Hospital.
Pertinent data collection was done through face-to-face interviews using structured questions. The patients were asked detailed questions about nephrology care before the initiation of HD, time of start of nephrology care in relation to time of initiation of dialysis, and vascular access at the initiation of dialysis. The questions were formulated by the researcher and answered by the patient through an interview done either before, after, or during the HD treatment session. Patients’ medical records were used to collect pertinent data and background and demographic information. Demographic data collected included age, sex, weight, height, body mass index (BMI), and home location in reference to dialysis unit (as measured through average time to get to unit from residence). Data on cause of ESRD: diabetes mellitus (DM), hypertension, poly-CKD, glomerulonephritis, other, or unknown were recorded. The presence of comorbidities including DM, hypertension, dyslipidemia, coronary artery disease, or cerebrovascular disease was also obtained.
Data pertaining to HD initiation and access were collected including the date of initiation of dialysis and current access method. Data on when the patients started seeing a nephrologist; in the three months preceding the initiation of dialysis or the previous year or earlier than one-year, were specifically explored.
| Statistical Analysis|| |
Data were summarized by calculating means and standard deviation (SD) or median and range for quantitative variables and percentages for categorical variables. The effect of early nephrology referral was assessed at different time points (starting <3 months, 3–12 months, and >12 months before dialysis initiation). Descriptive terms were used where appropriate. The analysis was performed using JMP® Pro 13.0.0.
| Results|| |
A total of 104 patients were undergoing regular HD at the designated unit during the study period. Of these, 93 patients were enrolled in the study. Eleven patients were excluded from the study (4 declined to participate, 3 patients did not have the ability to participate due to mental or other illness, three patients were not available/hospitalized at the time of the study, and one was a pediatric patient).
The mean age of the study participants was 50 ± 16 years. Forty-one (44%) were female. Average BMI was 25 ± 5. The cause of ESRD was DM in 28 (30%), hypertension in 28 (30%), polycystic kidney disease in three (3%), glomerulonephritis in three (3%), others in 17 (18%), and unknown in 14 (15%). Major associated comorbidities were DM in 29 (31%), hypertension in 60 (65%), dyslipidemia in 32 (34%), coronary artery disease in 13 (14%), and cerebrovascular disease in eight (9%). At the time of the study, patients had an average duration on dialysis of 72 months (range 1–240). Details of demographics are presented in [Table 1]. Type of HD vascular access at initiation of dialysis was CVC in 80 (86%) [of the 80, there were temporary non-tunneled-catheter in 51 (55% of the overall group) and permanent-tunneled in 29 (31% of the overall group)], AVF in 12 (13%), PD catheter in one (1%). The wait time between nephrology referral and fistula creation in months was one month with a range of one to eight months.
|Table 1: Baseline demographics and characteristics of the study participants.|
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Of the overall group, 50 (54%) were seen by a nephrologist before needing dialysis and 43 (46%) reported not having nephrology care before dialysis. The length of time from first nephrology contact to HD initiation in those followed in nephrology clinics was 4.6 years (SD 4.3). Of the ones who were seen in nephrology clinics, three (6%) had first nephrology evaluation in the three months before starting dialysis, and eight (16%) had nephrology evaluation in the 12 months prior to starting dialysis. The others (39 patients) were followed up by nephrology starting more than one year before HD initiation [Table 2]. In the overall study group, of the patients who initiated dialysis with a CVC (n = 80), 38 (48%) had received prior nephrology care and 42 (52%) received no prior nephrology care. Of the patients who initiated dialysis with an AVF (n = 12), 12 (100%) had received prior nephrology care. Of the 50 patients who received nephrology care before dialysis initiation, 12 patients (24%) had started dialysis with an AVF; in patients without prior nephrology care, all patients were started on HD with a CVC [Table 3].
|Table 3: Initial access characteristics according to predialysis follow-up.|
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Of the 39 patients who had nephrology care longer than one year prior to HD initiation, nine patients (23%) had initiated HD through AVF. Of the eight patients who had nephrology care within one year, but not within three months of HD initiation, two (25%) started HD with an AVF. In patients who had initiated HD with an AVF (n = 12), one had nephrology care within three months of HD, two had nephrology care within 12 months of dialysis, and nine patients(82%) had received nephrology care longer than one year [Table 4].
|Table 4: Initial access characteristics according to duration of pre-dialysis nephrology care.|
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| Discussion|| |
This study is the first to explore the prevalence of nephrology care before dialysis initiation in Jordanian patients and assess its impact on type of dialysis vascular access at initiation of dialysis. Our study showed that 54% of patients in this large HD unit in Jordan had nephrology care prior to dialysis initiation. Of these patients, 78% (42% of the entire study group) had nephrology care for longer than one year prior to initiation of dialysis. As such, less than half of the patients initiating dialysis in this group had early referral to nephrology.
For patients with CKD, Kidney Disease Improving Global Outcomes 2012 guidelines recommend referral to nephrology when the glomerular filtration rate drops below 30 mL/min/l.73 m2. However, multiple studies have shown that only a subset of patients who initiate dialysis have had prior nephrology care and that nephrology care is often late, with late referral to nephrology being variably defined as care starting <1 to 12 months before the initiation of dialysis.,,, In a large group of ESRD patients in the United States, among 443,761 incident ESRD patients between 2006 and 2010, 33% of new ESRD patients had received no prior nephrology care, while only 28% had received care for >12 months. Another study found that amongst elderly patients initiating dialysis, 46% percent had no predialysis nephrology care. In a large cohort of CKD patients from Korea, 38% of patients who initiated dialysis were referred late (<1 year before dialysis initiation).
Use of AVF as the access method in HD patients compared with CVC, has been associated with improved morbidity and mortality and decreased risk of infection leading to recommendations to increase its utilization in HD patients.,, However, most patients continue to initiate HD through a CVC, and investigation of causes of suboptimal utilization of AVF is of interest. In the current study, we found that 86% of patients initiated dialysis with a CVC with the remaining patients using an AVF as the initial access. One aspect that has been associated with increased AVF use at the start of dialysis is early referral to nephrology. Astor et al reported in a cohort of 356 patients, the ones who had been seen by a nephrologist at least one month before starting HD therapy were significantly more likely than those referred later to use an AVF as access at initiation (39% versus 10%) and at six months after starting HD therapy (74% versus 56%). In this study, patients referred within one month of initiating HD therapy used a dialysis catheter for a median of 202 days compared with 19 days for patients referred >12 months before initia-ting HD therapy. Another investigation from the US found that late referral to nephrology (defined in this study as referral after patients reached CKD stage 5), was associated with less permanent vascular access for initiation of dialysis. In our study, we found that patients who had predialysis nephrology care were more likely to start dialysis with an AVF (24% vs. 0 in the predialysis nephrology care vs no pre-dialysis care groups). However, the rate of AVF use at dialysis initiation was not different between those who were seen by nephrology, either longer or < 1 year prior to dialysis initiation.
There are other compelling reasons to consider nephrology referral in this population. Early referral to nephrology may be associated with decreased mortality in dialysis patients. In a large meta-analysis of 22 studies, there was significantly increased overall mortality in the late referral group as compared with the early referral group. In another systematic review of 27 longitudinal cohort studies with 17,646 subjects, comparing outcomes of early versus late nephrology referral in CKD, it was found that subjects who were referred early had reduced mortality and hospitalization, and had earlier placement of AVF for HD. Using the United States Renal Data System data to evaluate the impact of early nephrology referral and pre–ESRD care on mortality risk in a national cohort of new patients starting dialysis therapy in 1996 and 1997, it was found that late referral (defined in this study as within 4 months of dialysis) was associated with significantly increased mortality compared to those who saw a nephrologist earlier than that. Similar findings have been reported in other parts of the world.,
Early referral of CKD patients to nephrology may also be associated with decreased healthcare costs, delayed progression to ESRD, relatively shorter hospital stay at time of initiation of dialysis, higher albumin and hemoglobin, relatively lower phosphorus and parathyroid hormone levels, choice of PD and improved quality of life.,,,,, In addition to early referral advantage, there is also evidence that more frequent nephrology care before dialysis initiation is associated with increased likelihood of having permanent vascular access at dialysis initiation, and decreased mortality in the first two years after dialysis initiation. In our review of the literature, relatively limited data were found from developing countries in this field and this study serves to add to the understanding of nephrology referral rates and impact on dialysis access in such settings. Future studies are needed to further assess patterns of nephrology referral and its impact on other outcomes such as quality of life and mortality in patients in developing countries.
| Conclusion|| |
In this sample population from HD patients in Jordan, a large percentage of patients did not have any previous nephrology care before initiating dialysis. The ones who were followed by nephrology before dialysis, even as late as within three months before dialysis initiation, were significantly more likely to initiate dialysis using an AVF. In the studied group, all the patients not seen by nephrology prior to dialysis initiated dialysis through a CVC. A national focus on improving nephrology referral in advanced CKD may allow better utilization of AVF as the method of access at dialysis initiation.
Conflict of interest: None declared.
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Abdurrahman M Hamadah
Department of Internal Medicine, Faculty of Medicine, Hashemite University, Zarqa
[Table 1], [Table 2], [Table 3], [Table 4]