Download Two-times weekly hemodialysis in China: frequency, associated

Nephrol Dial Transplant (2014) 29: 1770–1777
doi: 10.1093/ndt/gft472
Advance Access publication 8 December 2013
Original Article
Two-times weekly hemodialysis in China: frequency,
associated patient and treatment characteristics and Quality of
Life in the China Dialysis Outcomes and Practice Patterns study
Brian Bieber1*, Jiaqi Qian2,*, Shuchi Anand3, Yucheng Yan2, Nan Chen4, Mia Wang1, Mei Wang5, Li Zuo6,7,
Fan Fan Hou8, Ronald L. Pisoni1, Bruce M. Robinson1 and Sylvia P.B. Ramirez1
1
Arbor Research Collaborative for Health, Ann Arbor, MI, USA, 2Renal Division, Renji Hospital, Shanghai Jiaotong University School of
Medicine, Shanghai, China, 3Division of Nephrology, Stanford University School of Medicine, Palo Alto, CA, USA, 4Department of Nephrology,
Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, 5People’s Hospital, Peking University, Beijing, China,
6
Peking University First Hospital, Beijing, China, 7Institute of Nephrology, Peking University, Beijing, China and 8Division of Nephrology,
Nanfang Hospital, Southern Medical University, Guangzhou, China
Correspondence and offprint requests to: B. Bieber; E-mail: [email protected]
*
Co-first author.
associated with dialyzing two times weekly (versus three times
weekly). Patients dialyzing two times per week had longer
treatment times and lower standardized Kt/V, but similar
quality of life scores.
Conclusions. Two-times weekly dialysis is common in China,
particularly among patients, who started dialysis more recently, have a lower comorbidity burden and have financial constraints. Quality of life scores do not differ between the twotimes and three-times weekly groups. The effect on clinical
outcomes merits further study.
A B S T R AC T
Background. Renal replacement therapy is rapidly expanding
in China, and two-times weekly dialysis is common, but detailed data on practice patterns are currently limited. Using
cross-sectional data from the China Dialysis Outcomes and
Practice Patterns Study (DOPPS), we describe the hemodialysis practice in China compared with other DOPPS countries,
examining demographic, social and clinical characteristics of
patients on two-times weekly dialysis.
Methods. The DOPPS protocol was implemented in 2011
among a cross-section of 1379 patients in 45 facilities in
Beijing, Guangzhou and Shanghai. Data from China were
compared with a cross section of 11 054 patients from the core
DOPPS countries (collected 2009–11). Among China DOPPS
patients, logistic and linear regression were used to describe
the association of dialysis frequency with patient and treatment characteristics and quality of life.
Results. A total of 26% of the patients in China were dialyzing
two times weekly, compared with < 5% in other DOPPS
regions. Standardized Kt/V was lowest in China (2.01) compared with other regions (2.12–2.27). Female sex, shorter dialysis vintage, lower socioeconomic status, less health insurance
coverage, and lack of diabetes and hypertension were
© The Author 2013. Published by Oxford University Press
on behalf of ERA-EDTA. All rights reserved.
Keywords: hemodialysis adequacy, hemodialysis frequency,
outcomes, practice patterns, quality of life
INTRODUCTION
The prevalence of chronic kidney disease (CKD) in China approaches that of the United States [1]. The use of renal replacement therapy (RRT) for patients reaching end-stage renal
disease (ESRD) is rising rapidly: in Shanghai, the incidence of
RRT more than doubled between 2000 and 2005 [2]. Though
there are regional variations, a majority of patients with ESRD
are on hemodialysis (HD) [3]. However, data on HD practice
and outcomes remain sparse.
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M AT E R I A L S A N D M E T H O D S
Patients and data collection
Begun in 1996, the DOPPS is an international prospective
cohort study of HD patients ≥18 years of age in Australia,
Belgium, Canada, France, Germany, Italy, Japan, New
Zealand, Spain, Sweden, the United Kingdom and the United
States (core DOPPS countries). Patients in the DOPPS are selected randomly from a representative sample of HD facilities
within each nation [10, 11]. In 2011, cross-sectional data were
collected in China using the baseline DOPPS questionnaires
and study protocols. Due to feasibility considerations, the
China study was limited to representative data from the metropolitan areas in the three largest cities in China (Beijing,
Guangzhou and Shanghai). These cities were identified based
on feasibility of data collection and availability of registry information should a comparison between DOPPS and registry
data be required. In each metropolitan area, 15 HD facilities
were randomly selected from a comprehensive roster of HD
units (total selected Chinese HD facilities = 45). Study approval and patient consent were obtained as required by national
and local ethics committee regulations.
A study coordinator at each participating site collected clinical data. At the time of patient enrollment, the study coordinator abstracted demographic data, comorbid conditions,
laboratory values, insurance status and medications from
patient records. Practice-level data were obtained through a
survey administered to the medical director at each facility. Individual patients completed a questionnaire that included the
Kidney Disease Quality of Life-Short Form (KDQOL-SF) 12
China DOPPS dialysis adequacy and vascular access
and questions related to socioeconomic status [12, 13]. Singlepool Kt/V was calculated using the Daugirdas formula among
patients dialyzing 3 × per week for at least 1 year. To account
for patients dialyzing at a frequency other than three times per
week, a standardized Kt/V was calculated from the equation
reported by Leypoldt et al. [14]. Normalized protein catabolic
rate (nPCR) was calculated by the equations reported by
Depner and Daugirdas [15].
Data from 10 947 patients sampled in the DOPPS 4 prevalent cross section of HD patients in the core DOPPS countries
between 2009 and 2011 were compared with data from 1379
prevalent Chinese patients collected in 2011. Standard descriptive analyses were used to characterize the DOPPS patients and practices in each country as well as within China, by
frequency of dialysis. Generalized estimating equation (GEE)
models with a logit link were used to describe the adjusted association of patient characteristics with two-times (versus
three-times) per week HD, accounting for facility clustering.
Mixed models were used to describe the adjusted association
between HD frequency and laboratory values and quality of
life, accounting for facility clustering. All analyses used SAS
software, version 9.2 (SAS Institute, Cary, NC).
R E S U LT S
Facility and patient characteristics
Of the 45 sampled facilities from the three metropolitan
areas in China (Beijing, Guangzhou and Shanghai), 23 were
academic or military facilities and 22 were non-academic facilities. On average, the Chinese facilities treated a comparable
number of HD patients (95) to facilities in Japan (97). In contrast, facilities in North America and Europe-Australia/New
Zealand (EUR-A/NZ) treated substantially fewer patients on
average (∼72) (Table 1).
Compared with study patients in the other DOPPS regions,
the Chinese patients were younger, more likely to be female
and less likely to have diabetes as the cause of ESRD (Table 1).
Time on dialysis in China was comparable with that in North
America and Eur-A/NZ, but shorter than in Japan. The
average body mass index (BMI) among patients in China was
similar to that in Japan but lower than in North America and
Eur-A/NZ.
Dialysis access and prescription
A native arteriovenous (AV) fistula for HD access was used
by 88% of China DOPPS patients compared with 91% in
Japan, 58% in North America and 70% in Eur-A/NZ
(Table 1). The mean number of prescribed HD sessions per
week was lower in China (2.8) than in the other DOPPS countries (range 3.0–3.1) (Table 1, Figure 1A). Twenty-six percent
of HD patients in China were dialyzing less than three times
weekly (88% of this group were undergoing two-times weekly
dialysis) compared with 1–6% in other DOPPS countries. The
median Chinese facility reported 26% of patients dialyzing less
than three times weekly (22% two times weekly) compared
with a range of 0–4% for the median facility in other DOPPS
countries (Figure 1B).
1771
ORIGINAL ARTICLE
The recently launched Chinese Renal Data System and
published data from city registries have reported that a significant proportion of patients are on two-times weekly HD [2, 4–
6]. Given that patients may shoulder a significant share of cost
for HD care in China [7], complex factors—such as patients’
comorbidity burden, residual function, preference to start HD
gradually and insurance status—may underlie a decision to
pursue two-times weekly dialysis. The effect on Chinese patients’ health-related quality of life (HR-QOL) and survival is
unknown.
Using cross-sectional data from the China Dialysis Outcomes and Practice Patterns (DOPPS) study, we describe the
current state of HD in China in comparison with other
DOPPS countries. We also tested the hypothesis that the decision to pursue two-times weekly HD would be related to both
clinical and economic factors. As such, we expected that patients with lower comorbidity burden, greater residual function, shorter dialysis vintage (i.e., years since initiation of
dialysis) and greater share of cost for treatment would be more
likely to undergo two-times weekly HD. Despite attempts to
select a ‘healthier’ group of patients for less frequent dialysis,
we expected that this group would face a greater likelihood of
‘inadequate’ dialysis therapy and require strict diet restrictions.
We therefore hypothesized that this group would exhibit
poorer control of anemia and markers of mineral-bone
disease, and experience worse quality of life [8, 9].
Table 1. Facility and patient characteristics by region
ORIGINAL ARTICLE
Measure
Facility characteristics
Facility, n
Facility size
Facility size, range
Patient demographics
Study population, n
Age, years
Female, %
Time on dialysis, years
Urine output >1 cup/day, %a
BMI, kg/m2
Comorbidities
Cause of ESRD, %
Diabetes
Glomerular disease
Other
Comorbidities, %
Coronary heart disease
Congestive heart failure
Cerebrovascular disease
Peripheral vascular disease
Other cardiovascular disease
Diabetes
Hypertension
Dialysis prescription
# Prescribed HD sessions/week
Dialysis session length, min
Blood flow rate, mL/min
Single-pool Kt/V b
Single-pool Kt/V <1.2, %b
Standardized Kt/V c
Standardized Kt/V <2.0c
Intra-dialytic weight loss, %
Vascular access, %
Fistula
Graft
Catheter
Labs
BUN, mg/dL
Pre-dialysis
Post-dialysis
nPCR, g urea nitrogen/kg/day
Urea reduction ratio, %
Serum calcium, mg/dLd
Serum albumin, g/dL
Serum PTH, pg/mL
Serum phosphorus, mg/dL
Hemoglobin, g/dL
Quality of Life
Physical component summary
Mental component
China
Japan
North America
Eur-A/NZe
45
95 (74)
21–379
60
97 (73)
20–411
167
72 (53)
20–294
157
71 (35)
21–216
1379
59.4 (14.6)
46.6
4.8 (4.6)
62
21.9 (3.5)
1587
64.7 (12.0)
37.3
8.5 (7.5)
51.5
21.1 (3.3)
5106
62.9 (15.1)
44.5
4.0 (4.2)
46.8
28.5 (7.0)
4361
65.9 (14.7)
40.7
5.0 (5.7)
56.8
26.0 (5.5)
20.2
46.1
33.8
31.7
44.8
23.5
42.5
11.3
46.2
25.0
19.7
55.3
38.3
31.5
17.8
10.8
28.0
24.0
89.5
32.8
21.0
15.7
19.8
32.5
35.2
79.6
48.5
35.5
18.0
34.9
29.6
61.2
93.6
38.8
20.9
18.0
34.9
34.5
36.1
84.3
2.76 (0.55)
243 (22)
235 (30)
1.38 (0.31)
29.1
2.01 (0.41)
42.8
4.1 (2.0)
2.96 (0.21)
237 (29)
202 (29)
1.42 (0.26)
19.3
2.12 (0.28)
25.3
3.9 (1.7)
2.98 (0.24)
218 (34)
413 (68)
1.59 (0.27)
6.5
2.23 (0.28)
13.8
3.1 (1.7)
3.03 (0.33)
245 (39)
317 (57)
1.58 (0.31)
9.6
2.27(0.32)
14.3
2.8 (1.6)
88.0
1.8
10.2
90.7
7.0
2.3
57.8
17.5
24.7
69.7
7.3
23.1
49.2 (22.1)
15.7 (9.8)
0.80 (0.31)
67.8 (10.4)
9.0 (1.0)
3.9 (0.5)
386 (410)
6.1 (2.1)
10.5 (2.0)
66.5 (15.4)
21.3 (7.0)
1.01 (0.21)
67.9 (7.2)
9.2 (0.8)
3.7 (0.4)
167 (161)
5.5 (1.4)
10.4 ((1.2)
55.9 (18.7)
15.1 (7.2)
0.96 (0.26)
73.3 (7.4)
9.2 (0.7)
3.8 (0.4)
350(315)
5.3 (1.6)
11.5 (1.2)
62.0 (20.2)
17.2 (8.8)
1.08 (0.28)
72.7 (8.5)
9.2 (0.8)
3.7 (0.5)
312 (302)
5.0 (1.6)
11.5 (1.4)
36.2 (9.2)
43.8 (9.3)
42.5 (10.0)
43.4 (9.3)
35.4 (10.7)
47.4 (10.8)
34.9 (10.6)
44.7 (12.4)
EUR-A/NZ, Europe-Australia/New Zealand; BMI, body mass index; ESRD, end-stage renal disease; HD, hemodialysis; BUN, blood urea nitrogen; nPCR, normalized protein catabolic
rate; PTH, parathyroid hormone.
Mean values are shown with (standard deviation) in parentheses; all values missing for <10% of patients in China with the exception of single-pool Kt/V b (39%), and standardized Kt/V c
(45%), post-dialysis BUN (31%), albumin adjusted calcium (15%), PTH (23%) and quality of life (22%).
a
Restricted to patients having ESRD <1 year.
b
Restricted to patients having ESRD ≥1 year, and received 3 HD sessions per week; single-pool Kt/V was calculated using the Daugirdas formula.
c
To account for patients dialyzing at a frequency other than 3× per week, a standardized Kt/V was calculated from the equation reported by Leypoldt et al. [14].
d
Albumin-adjusted calcium.
e
The European DOPPS countries include Belgium, France, Germany, Italy, Spain, Sweden, and the United Kingdom.
The mean HD session length in Chinese facilities (243
min) was comparable with that in Eur-A/NZ (245 min) and
Japan (237 min) but higher than that in North America (218
min) (Table 1). Session length did not vary greatly among
1772
Chinese facilities, with half of all Chinese facilities reporting a
mean treatment time of ≥240 min, the fourth highest among
the DOPPS countries. The mean blood flow rate of 235 mL/
min was somewhat higher than in Japan (202 mL/min) but
B. Bieber et al.
ORIGINAL ARTICLE
F I G U R E 1 : Frequency of dialysis sessions/week by country: (A) patient frequency categories, (B) distribution of facility % of patients dialyzing
<3× per week. † Among facilities with at least 7 patients with non-missing frequency data.
markedly lower than in North America (414) and Eur-A/NZ
(317) (Table 1).
Among patients on HD for at least 1 year who dialyzed
three times per week, mean single-pool Kt/V in Chinese facilities (1.38) was lower than that seen in other DOPPS regions,
and for these patients, more had Kt/V < 1.2 in China (29%)
than in other DOPPS countries (Table 1). Accounting for
number of sessions per week, the average standardized Kt/V
was lowest in China (2.01) compared with other DOPPS
regions (2.12–2.27), and China had the highest proportion of
patients with a standardized Kt/V < 2.0 (43 versus 14–25%).
Laboratory values and quality of life
Pre-dialysis blood urea nitrogen (BUN) was markedly
lower in the China DOPPS patients (49.2 mg/dL) than in
other DOPPS regions (range, 55.9–66.5 mg/dL) (Table 1).
nPCR was lower in China (0.8) than in other DOPPS regions
(0.96–1.08). Serum phosphorus (6.1 mg/dL), serum albumin
(3.9 g/dL) and intra-dialytic weight loss (IDWL, 4.1%) were
higher in China than in other DOPPS regions. Average
China DOPPS dialysis adequacy and vascular access
hemoglobin levels in China (10.5 g/dL) were comparable with
Japan (10.4) but lower than in Eur-A/NZ and North America
(11.5). Overall, the quality of life in China was similar when
compared with other DOPPS regions.
Characteristics of patients on two-times weekly HD in
China
Restricting to patients dialyzing two or three times per
week in China (95% of the China DOPPS sample), patients
dialyzing two times weekly were more likely to be female, had
shorter vintage (23% were on dialysis for < 1 year) and were
more likely to have residual urine output (Table 2). They also
had a lower comorbidity burden, particularly of diabetes,
hypertension and coronary heart disease. Patients with <12
years of education, those bearing higher out-of-pocket costs
(Table 2 footnote) or without national health insurance coverage were much more likely to receive two-times weekly HD,
whereas patients who had retired or had close to full coverage
from the national health insurance were much less likely to be
on two-times weekly HD. Finally, lack of sufficient HD station
1773
Table 2. China DOPPS: Patient characteristics associated with odds of dialyzing two times versus three times per week
ORIGINAL ARTICLE
Mean (SD) or %
Odds ratio: 2 sessions per week versus 3
Patient characteristics
2× per week(n = 304)
3× per week(n = 982)
Unadjusteda,OR (95% CI)
Age, years [OR per 10 years]
Female, %
Dialysis vintage, years
BMI, kg/m2
Urine output >200 mL/day, %
<12 years education
Employment status
Unemployed
Retired
Employed and otherc
Health insuranced,e
No national insurance
Nat. ins. coverage <50%
Nat. ins. coverage 50–84%
Nat. ins. coverage 85–94%
Nat. ins. coverage 95+%
Comorbidities, % [OR – yes versus no]
Coronary heart disease
Congestive heart failure
Cerebrovascular disease
Peripheral vascular disease
Other cardiovascular disease
Diabetes
Hypertension
59.0 (15.2)
52.0
3.51 (3.54)
21.6 (3.4)
52.5
14.8
59.6 (14.4)
44.6
5.16 (4.82)
21.9 (3.6)
25.1
8.7
0.95 (0.86–1.05)
1.31 (1.07–1.62)*
0.91 (0.86–0.95)*
0.98 (0.95–1.01)
3.39 (2.33–4.93)*
1.48 (1.07–2.04)*
Adjustedb,
OR (95% CI)
1.12 (0.99,1.26)
1.28 (1.06,1.54)*
0.94 (0.90,0.98)*
0.99 (0.96,1.02)
2.92 (1.92,4.43)*
1.55 (1.08,2.21)*
20.1
53.3
26.6
10.1
70.8
19.0
1.13 (0.79–1.63)
0.48 (0.35–0.65)*
(ref)
1.07 (0.74,1.54)
0.55 (0.39,0.77)*
(ref)
7.9
5.0
24.8
29.7
25.4
2.0
3.2
18.6
32.9
36.1
4.45 (2.13–9.33)*
2.34 (0.95–5.75)
2.03 (1.38–2.99)*
(ref)
0.67 (0.48–0.95)*
2.49 (1.04,5.92)*
1.89 (0.74,4.87)
1.44 (0.96,2.17)
(ref)
0.69 (0.48,0.99)*
34.9
30.6
16.4
10.2
25.7
16.9
85.5
39.7
32.3
18.5
10.8
28.8
26.1
90.9
0.78 (0.61–1.00)
0.94 (0.68–1.30)
0.80 (0.53–1.18)
0.92 (0.58–1.45)
0.85 (0.62–1.16)
0.54 (0.39–0.75)*
0.51 (0.32–0.81)*
1.03 (0.78,1.36)
0.97 (0.72,1.29)
0.92 (0.60,1.42)
1.12 (0.65,1.93)
1.02 (0.71,1.47)
0.49 (0.34,0.71)*
0.51 (0.31,0.83)*
Mean values are shown with (standard deviation) in parentheses.
a
Accounting for facility clustering.
b
Adjusted for variables listed in Table 1.
c
‘Other’ employment status includes ‘employed full time’ (7%), ‘employed part time’ (7%), ‘homemaker’(7%) and ‘disabled’ (0.1%).
d
7% of patients were missing data on the % of national health insurance.
e
Patient-reported out-of-pocket medical healthcare costs were 2588 versus 1831 yuan for two-times weekly versus three-times weekly HD (unadjusted OR = 1.01 per 100 yuan, 95%
CI = 1.00, 1.02, P < 0.01). Out-of-pocket healthcare costs were calculated as the sum of monthly dialysis, supplemental insurance, prescription medication and non-prescription
medication costs. Out-of-pocket healthcare costs were highly correlated with level of national insurance coverage so only insurance coverage was included as covariate in table.
*P < 0.05.
capacity was rare in China (only cited by 3 of 44 medical directors in a survey regarding facility practices and resources) and
was not associated with patients receiving two-times weekly
HD (P = 0.63).
Dialysis-related prescriptions, laboratory values and
quality of life associated with two-times weekly HD in
China
Patients dialyzing two times weekly (versus three times) in
China were much more likely to be prescribed session lengths
>270 or 300+ min (Table 3). On a weekly basis, these patients
were dialyzed for an average of 8.4 h compared with 12.0 h for
patients dialyzing three times weekly. Average blood flow rates
and vascular access were similar. Patients dialyzing two times
weekly (versus three times) in China had similar erythropoietin-stimulating agent prescription rates (95%) but were less
likely to be prescribed intravenous iron (33 versus 43%),
vitamin D (48 versus 60%) or a phosphate binder (52 versus
60%).
Chinese patients dialyzing two times weekly had substantially lower mean weekly clearance (Table 4, standardized Kt/
1774
Table 3. China DOPPS: Dialysis session prescription patterns in patients
dialyzing two times versus three times per week
Mean (SD) or %
Odds ratio (OR) or difference
(β): 2× (versus 3×)
Dialysis session
prescriptions
2× per
week
(n = 304)
3× per
week
(n = 982)
Unadjusteda,
OR or β (95%
CI)
Adjustedb,
OR or β
(95% CI)
Session length,
min (OR: >240
versus ≤240)
< 240 min
240 min
270 min
300+ min
Blood flow rate,
mL/min
Catheter use, %
(OR: versus
fistula)
253 (28)
240 (17)
5.55 (2.88–
10.68)*
6.82 (2.97–
15.63)*
5
65
10
20
233 (33)
7
88
4
1
235 (28)
11
10
+0.2 (−3.0,3.4) +0.4
(−2.9,3.7)
1.00 (0.68–
0.64 (0.38–
1.47)
1.09)
Mean values are shown with (standard deviation) in parentheses.
a
Accounting for facility clustering.
b
Adjusted for variables listed in Table 2 and all other treatment variables listed in Table 3.
*P < 0.05.
B. Bieber et al.
Table 4. China DOPPS: Laboratory values and quality of life in patients dialyzing two times versus three times per week
Mean (SD)
Outcome measures
Urea reduction ratio, %
Standardized Kt/V c
Intradialytic weight loss, %
nPCR, g urea nitrogen/kg/day
Serum calciumAlb, mg/dLd
Serum albumin, g/dL
Serum PTH, pg/mL
Serum phosphorus, mg/dL
Hemoglobin, g/dL
QoL: SF-12 physical component summary
QoL: SF-12 mental component summary
2× per week(n = 304)
69.1 (11.4)
1.45 (0.19)
4.1 (2.5)
0.68 (0.24)
8.7 (1.1)
4.0 (0.5)
398 (425)
6.3 (2.3)
10.2 (2.2)
36.7 (9.5)
43.4 (9.0)
Difference (β): 2× (versus 3×)
3× per week(n = 982)
67.4 (10.0)
2.11 (0.26)
4.1 (1.8)
0.83 (0.32)
9.1 (1.0)
3.9 (0.5)
376 (408)
6.0 (2.1)
10.6 (2.0)
36.1 (9.1)
43.8 (9.5)
Unadjusteda,β (95% CI)
+2.02 (0.39,3.66)*
−0.67 (−0.72, −0.62)*
−0.02 (−0.28,0.25)
−0.13 (−0.17, −0.09)*
−0.35 (−0.49, −0.21)*
+0.06 (−0.01,0.12)
+20.6 (−44.2,85.4)
+0.22 (−0.07,0.51)
−0.31 (−0.57, −0.04)*
+0.78 (−0.57,2.14)
−0.24 (−1.61,1.14)
Adjustedb,β (95% CI)
+0.29 (−1.45,2.02)
−0.73 (−0.77, −0.69)*
+0.25 (−0.03,0.52)
−0.16 (−0.20, −0.11)*
−0.26 (−0.42, −0.10)*
+0.03 (−0.03,0.10)
+65.3 (−5.3,135.9)
+0.25 (−0.08,0.57)
−0.23 (−0.53,0.07)
−0.61 (−2.03,0.82)
−1.13 (−2.72,0.45)
Mean values are shown with (standard deviation) in parentheses.
a
Accounting for facility clustering.
b
Adjusted for variables listed in Tables 2 and 3, but not other variables in Table 4.
c
To account for patients dialyzing at a frequency other than 3× per week, a standardized Kt/V was calculated from the equation reported by Leypoldt et al. [14].
d
Albumin-adjusted calcium.
*P < 0.05.
DISCUSSION
We report data on patient characteristics, and HD access and
prescription practices from a representative sample of 45 HD
units in three major Chinese metropolitan areas. To our
knowledge, these are the first analyses that utilize comparable
data collection methods in China and other countries, allowing us to present systematic comparisons in practice patterns
between the three cities in China and other DOPPS countries.
Preliminary findings suggest important differences in the
patient population as well as HD-prescribing practices in
China compared with other DOPPS countries.
Chinese patients were younger, had smaller body size as
measured by BMI and experienced a generally lower co-morbidity burden, when compared with other DOPPS countries.
The proportion with diabetic nephropathy was also lower than
other DOPPS countries. A majority of Chinese patients used a
native AV fistula for HD therapy, while the prescribed access
blood flow rate was considerably lower in Chinese HD facilities
than that seen in other DOPPS countries, with the exception
of Japan. Most strikingly, at least a quarter of Chinese patients
underwent HD two times weekly compared with fewer than
5% in most DOPPS countries. Furthermore, 29% of Chinese
patients dialyzing three times per week achieved a Kt/V < 1.2
compared with at or below 10% in the majority of DOPPS
countries.
China DOPPS dialysis adequacy and vascular access
The sizeable fraction of patients undergoing two-times
weekly HD in our study is consistent with that reported by
single city registry data in China. Twenty-eight percent of registered Beijing patients were undergoing two-times weekly
HD in 2002, according to the Beijing Hemodialysis Quality
Control and Improvement Center [4]. The 2005 Shanghai Dialysis Registry reported patients were dialyzing for an average of
2.6 times per week, similar to the 2.8 times per week observed
in our study [2].
One Chinese study limited to Shanghai has previously
characterized this population of patients undergoing twotimes weekly HD. Lin et al. [5] followed ∼2500 patients in
Shanghai for a period of 2 years. In their cohort, patients on
two-times (versus three times) weekly HD were younger, had
lower body surface area, shorter vintage on HD and higher
serum albumin concentrations. Similarly, in our study, patients on two-times weekly HD had shorter vintage, greater residual function and a lower comorbidity burden. We also
found that women were more likely to be prescribed this frequency, and we hypothesize that this may be due to their
smaller body size. Their findings as well as ours indicate that
Chinese nephrologists are prescribing two-times weekly HD to
patients who are relatively healthier and potentially more able
to ‘tolerate’ the less intensive fluid and electrolyte management.
In addition, we found that patients without national insurance were more likely to be on two-times weekly HD. In fact,
many patients without national insurance may not be able to
access treatment at all. Although newly implemented insurance policies subsidize treatment to some extent for some patients (e.g. government employees), large co-payments for HD
therapy (annual total cost $7500) likely severely strain patient
resources [7]. For example, a dialysis center from China’s
Guangxi province reported that one-third of patients presenting with advanced CKD refused initiation of RRT; a majority
cited the cost of HD therapy as a deterrent [1]. For patients
who do initiate treatment, reducing frequency of treatment
1775
ORIGINAL ARTICLE
V difference = −0.67) and nPCR (−0.16 g urea nitrogen/kg/
day). They also had lower levels of serum calcium (−0.26),
with a suggestion of higher average serum phosphorous levels
and parathyroid hormone (PTH) levels and lower hemoglobin.
Serum levels of albumin among patients dialyzing two times
weekly were comparable with those dialyzing three times per
week. There was no meaningful difference in reported quality
of life for patients dialyzing two times versus three times
weekly.
ORIGINAL ARTICLE
may be an important method of defraying direct and indirect
(travel) costs. These constraints, not experienced by patients
living in most other established DOPPS countries, are the
likely basis for ‘the frequency decision’ in a majority of cases.
Our data on medications support this conclusion. Despite laboratory values demonstrating equivalent to slightly poorer
control of mineral bone disease and anemia among patients
undergoing two-times weekly HD, this group was much less
likely to be taking phosphate binders, vitamin D analogs or
iron than the group undergoing three-times weekly HD. This
discrepancy again points to potential financial constraints that
may limit access to a variety of treatments in the two-times
weekly group.
In the United States, the National Kidney Foundation/
Kidney Disease Outcomes Quality Initiative clinical practice
guidelines recommend at least three-times weekly HD for individuals with <3 mL/min/1.73 m2 of residual kidney urea
clearance [16]. Aside from necessitating stricter restrictions on
fluid and electrolyte intake, two-times weekly HD can be expected to increase time-average urea concentrations and attenuate clearance of solutes with small volume of distribution
[17].
Clinical data on the effect of less frequent HD are sparse.
Lin et al. [5] reported that patients on two- or three-times
weekly HD had equivalent survival over a period of 2 years,
even for the subgroup on dialysis for >5 years. Another study
from Taiwan examined preservation of renal function among
23 patients undergoing two-times weekly HD compared with
51 patients undergoing three-times weekly HD [18]. After 18
months of follow-up, the study reported a slower decline in
renal function for two-times weekly patients, and similar nutrition and bone parameters in the two groups. In our study as
well, standardized Kt/V was significantly lower among patients
undergoing two-times weekly HD. There was a suggestion of
poorer laboratory indicators (including hypocalcemia, hyperphosphatemia and anemia) among patients undergoing twotimes weekly HD, which could reflect inadequacies in the delivered dose of dialysis but must be interpreted with caution
given that this group was also less likely to be taking supporting medications. The lower nPCR measurement among patients in the two-times weekly group also indicated that
patients were either following more strict protein restrictions
or were more malnourished, but their HR-QOL did not differ
from the patients undergoing three-times weekly HD.
These data raise the question of whether two-times weekly
HD may be appropriate for a select group, particularly given
the resource constraints of low- and middle-income countries.
However, a major methodological concern is confounding-byindication, as a selected healthier group may be prescribed
less-frequent HD, and the observed equivalent outcomes may
simply be a reflection of their underlying health and not an
evaluation of the dialysis prescription per se.
A longer and appropriately powered study examining survival, hospitalizations and HR-QOL—controlling for factors
such as age, comorbid conditions, residual function and HD
adequacy—can answer the question of whether less frequent
(but longer) prescriptions can support some Chinese patients
to yield outcomes that approach those with three-times per
1776
week frequency used in most DOPPS countries. The longitudinal component of China DOPPS, which began in autumn
2012, has the potential to address some of the methodological
issues that may be present in previously published studies.
Our study has several strengths. It is one of the first to
provide representative data describing practice patterns and
associated patient characteristics from a sample of three major
metropolitan areas—in a country new to widespread use of
HD therapy. The use of standard DOPPS protocols and questionnaires allows for comparisons with other DOPPS countries with well-documented HD practices. Furthermore, the
representative facility sampling in DOPPS allowed us to
compare the range of practices across facilities within each
studied region or country. We have validated data collected
from 42 of the 45 participating Chinese facilities through reabstraction of 25 data elements for seven randomly selected
study patients at each of these study sites via the use of an external data collector. There was a high level of agreement
between the data originally abstracted by the study coordinator
and the re-abstracted data for all variables included in this reliability study assessment.
Our results for China represent HD patients from three
large urban areas of China, with a total general population of
>50 million people. Although a majority of patients on HD are
concentrated in these types of urban areas, our study is likely
not representative of the overall Chinese HD population, and
we are not able to describe the unique set of challenges that patients and clinicians face in rural areas—including not being
able to capture patients who die without ever accessing treatment. The cross-sectional nature of the data to date limits us
to a determination of association without any ability to infer
causation. Detailed data on nutritional intake ( particularly
dietary protein) were not available. Finally, we could not describe practices and outcomes associated with peritoneal dialysis, although this modality is used by a minority of patients
undergoing dialytic therapy in China.
In summary, our study highlights important aspects of
patient characteristics and HD practices in China. Patients on
HD in China are generally younger and healthier than in most
other DOPPS countries. Most receive HD using a native AV
fistula. A substantial proportion are dialyzing two times
weekly; the patients dialyzing two times weekly have shorter
vintage, greater residual function, lower co-morbidity and/or
face having to pay a large share of cost for HD. A longitudinal
component of the China DOPPS in these three major metropolitan areas was initiated in autumn 2012, which will help
elucidate uncertainty regarding the outcomes associated with
practice differences identified in the current cross-sectional
analyses of Chinese HD patients.
AC K N O W L E D G E M E N T S
Heather Van Doren, MFA, a senior medical editor with Arbor
Research Collaborative for Health, provided editorial assistance on this manuscript. The DOPPS is administered by
Arbor Research Collaborative for Health and is supported by
scientific research grants from Amgen (since 1996), Kyowa
B. Bieber et al.
Hakko Kirin (since 1999, in Japan), Sanofi Renal (since
2009), AbbVie (since 2009), Baxter (since 2011) and Vifor
Fresenius Renal Pharma (since 2011), without restrictions on
publications.
C O N F L I C T O F I N T E R E S T S TAT E M E N T
The DOPPS is administered by Arbor Research Collaborative
for Health and is supported by scientific research grants from
Amgen (since 1996), Kyowa Hakko Kirin (since 1999, in
Japan), Sanofi Renal (since 2009), AbbVie (since 2009), Baxter
(since 2011) and Vifor Fresenius Renal Pharma (since 2011),
without restrictions on publications. The authors declare no
competing financial interests. The authors confirm that the
results presented in this paper have not been published previously in whole or in part, except in abstract form.
(See related article by Kalantar-Zadeh and Casino. Let us give
twice-weekly hemodialysis a chance: revisiting the taboo.
Nephrol Dial Transplant 2014; 29: 1618–1620.)
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China DOPPS dialysis adequacy and vascular access
Received for publication: 26.4.2013; Accepted in revised form: 9.10.2013
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