ABSTRACT
Aim
Anaemia is a significant complication of chronic kidney disease (CKD). However, its prevalence and treatment patterns in Asia are poorly understood. We sought to quantify prevalence of anaemia and its treatment in people with CKD across the region.
Methods
MEDLINE and Embase (inception to 2023) were systematically searched for observational studies of adults with CKD conducted in Asia that reported the prevalence of anaemia or its treatment. Additional relevant unpublished data were obtained from national experts. Summary estimates of the prevalence of anaemia and its treatment were determined using a random‐effects meta‐analysis according to country and study‐specific CKD inclusion criteria.
Results
Eighty‐six studies from 10 Asian countries reported data on 1 342 121 participants. The overall prevalence of anaemia in individuals with CKD was 42% (95% CI 33%–52%), with wide variation (12%–57% in studies including all CKD stages; 21%–96% in studies limited to individuals with kidney failure). Anaemia prevalence progressively increased with more advanced CKD (80% in Stage 5). Studies reporting data on anaemia treatment, particularly in early CKD, were limited. The prevalence of erythropoietin‐stimulating agents (ESAs) and iron therapy was 40% (95% CI 24%–58%) and 21% (95% CI 14%–31%), respectively (ESA: 7%–29% in CKD, 63%–95% in kidney failure; iron: 6%–26% in CKD, 15%–88% in kidney failure).
Conclusion
Our findings indicate a significant, but widely varying, prevalence of anaemia and its treatment in people with CKD in Asia. Substantial variability in data availability and collection highlights the need for standardised reporting to facilitate the development of regionally relevant strategies for anaemia management in CKD.
Keywords: anaemia, Asia, chronic kidney disease, erythropoietin, iron
1. Introduction
Chronic kidney disease (CKD) is a rapidly growing multisystem disorder affecting people globally, with the highest burden in Asia [1]. Anaemia, a frequent complication of CKD, is associated with increased mortality, as well as other adverse outcomes, including neurocognitive impairment, sleep disturbances, CKD progression, cardiovascular comorbidities and reduced quality of life (QoL) [2, 3, 4, 5, 6]. Anaemia of CKD develops from a combination of relative erythropoietin (EPO) deficiency, decreased responsiveness to EPO, iron deficiency, chronic inflammation and shortened red blood cell survival [7, 8].
Clinical practice guidelines, such as the European Best Practice Guidelines [9] and the Kidney Disease Improving Global Outcomes (KDIGO) Guidelines for anaemia in CKD (currently being updated) [10], recognise anaemia management as an integral part of overall CKD management. Although most prevalent in patients receiving dialysis, anaemia and its adverse effects have also been recognised in patients with earlier stages of CKD [11, 12]. Despite the availability of effective strategies to treat anaemia in CKD, such as erythropoiesis‐stimulating agents (ESAs), iron therapy, blood transfusion, and more recently, hypoxia‐inducible factor‐prolyl hydroxylase inhibitors (HIF‐PHIs), current evidence suggests that treatment of anaemia in CKD and dialysis populations remains suboptimal [13, 14, 15].
Much of the evidence on the burden and treatment of anaemia in CKD has been derived from Europe and North America; regional data from the countries in Asia, where the burden of CKD is high [16], are lacking. Reliable data on the prevalence and management of anaemia are needed to define the need and improve the care of people with CKD in this region. We thus systematically synthesised the available evidence on the prevalence of anaemia and its treatment in people with CKD in Asia.
2. Methods
2.1. Data Sources and Study Selection
We conducted a systematic review according to the Meta‐analysis of Observational Studies in Epidemiology (MOOSE) guidelines [17]. Studies were identified through a systematic literature search of MEDLINE and EMBASE from inception to May 2023. The search strategy was based on relevant text words and medical subject headings related to Asian countries (defined as South Asia, Southeast Asia and East Asia [18]), CKD, anaemia and anaemia treatment (Appendix S1). No language or date restrictions were placed. In addition, personal enquiry among collaborators and experts in the region was sought to obtain unpublished data through the Asian Renal Collaboration (ARC; a group of investigators representing and contributing cohort data on individuals with CKD from the Asia‐Pacific area [18]). Where available, individual participant data (IPD) were sought from collaborating studies; otherwise, summary‐level data were collected.
All cross‐sectional and longitudinal studies, which (1) included adult (age ≥ 18 years) populations from the Asia‐Pacific region, (2) reported the prevalence of anaemia and/or its treatment in individuals with CKD (defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2 and/or the presence of proteinuria, or as defined by authors) and (3) had ≥ 500 participants, were eligible for inclusion. When there was overlap in the cohort analysed across two or more studies, the most recent study was included. Studies published before the year 2000 or those that defined non‐dialysis dependent CKD (NDD‐CKD) and/or anaemia using administrative codes were excluded.
2.2. Data Collection and Quality Assessment
Titles, abstracts and relevant full‐text articles were assessed independently by two authors (DK and JL) to determine which studies met the inclusion criteria for the systematic review. Data extraction was conducted independently by two authors (DK and JL) using a standard data extraction form. Full‐text review and data extraction, where required, for non‐English articles were conducted by other members of the group. Disagreements in abstract screening and extracted data were adjudicated by a separate reviewer (MJ). The data sought included sociodemographic characteristics, comorbidities (type 2 diabetes mellitus, hypertension, cardiovascular disease, smoking history), baseline laboratory investigations (haemoglobin [Hb], serum creatinine, eGFR, serum ferritin, transferrin saturation), anaemia prevalence and anaemia treatment prevalence.
Study quality was judged independently by two authors (DK and JL) based on a modified version of the Newcastle‐Ottawa Quality Assessment Scale for cohort studies (Appendix S2) [19]. The criteria assessed were (1) representativeness of the cohort, (2) sample size (< 1800 vs. ≥ 1800 participants; based on the median sample size of the included studies), (3) outcome ascertainment (definition of anaemia used), (4) comparability of cohort characteristics (anaemic vs. non‐anaemic) and (5) reporting of descriptive statistics. For each domain, the study received a score of 0 (indicating the study did not meet the criteria requirement or there was insufficient information to determine whether the criteria requirement was met) or 1 (indicating the study met the criteria requirement). Low risk was defined as 6–7 points, moderate risk as 3–5 points and high risk of bias was defined as 0–2 points.
2.3. Definition of Anaemia and Its Treatment
Anaemia was defined as a haemoglobin concentration < 130 g/L in males and < 120 g/L in females, according to the KDIGO guidelines [10], or as defined by the study authors. Anaemia treatment was defined as the use of iron supplementation (including oral and intravenous), ESAs or HIF‐PHIs.
2.4. Data Synthesis and Analysis
Continuous variables were summarised using the mean and standard deviation or median and interquartile interval (IQI) and categorical variables as numbers with percentages. A web‐based application, WebPlotDigitizer, was utilised for extracting data from plots where required [20]. For each individual study, the prevalence of anaemia and its treatment (where reported) and the corresponding 95% confidence intervals (CIs) were calculated. Study‐level prevalence of anaemia and its treatment were then pooled within each country using a random‐effects inverse variance weighted meta‐analysis, and the I 2 statistic was used to estimate the percentage of between‐study variability.
To account for differences in CKD stages across the included studies, two sets of estimates were calculated for each country by categorising eligible studies as “CKD all stages” (according to the 2012 KDIGO Guidelines [21]) or “ESKD only” (defined as receiving maintenance dialysis or having a functioning kidney transplant). Studies defined as “CKD all stages” included individuals across the spectrum of CKD, while those defined as “ESKD only” were restricted to maintenance dialysis or kidney transplant recipients. Data describing anaemia treatment in early kidney disease were sparse. Therefore, anaemia treatment prevalence was pooled for stages 1 and 2 CKD.
To examine possible causes of heterogeneity (irrespective of country), subgroup analyses were performed by CKD stage (stages 1 to 5), mean age of the study cohort (< 60 years and ≥ 60 years), percentage of females in the study cohort (< 45% and ≥ 45%), percentage of individuals with diabetes (< 30% and ≥ 30%), percentage of individuals with hypertension (< 70% and ≥ 70%), percentage of individuals with cardiovascular disease (< 15% and ≥ 15%), mean eGFR (< 50 mL/min/1.73m2 and ≥ 50 mL/min/1.73m2) and definition of anaemia used (haemoglobin level < 130 g/L in males and < 120 g/L in females [as per the KDIGO guidelines] and other definitions). Subgroup thresholds were based on the overall mean baseline characteristics of all included studies.
All analyses were performed using R (version 4.1.3; R Foundation for Statistical Computing, Vienna, Austria) and STATA (version 18.0; StataCorp, College Station, TX).
3. Results
3.1. Studies and Participants
A total of 2303 articles were identified in the literature search, of which 237 were included for full‐text review. Seventy‐five articles from 73 distinct cohorts met the inclusion criteria (Table S1, Figure 1). In addition, unpublished data from 11 studies were also included (consisting of 2 IPD‐level dialysis datasets from India [n = 3972], 4 summary‐level datasets from Japan [n = 307 776], 1 summary‐level dialysis dataset from Malaysia [n = 57 988], 3 IPD‐level datasets from South Korea [n = 92 590] and 1 IPD‐level dialysis dataset from Thailand [n = 32 466]; Table S1). In total, 86 studies from 84 cohorts with 1 316 292 participants across 10 countries/regions (Brunei, China, India, Iran, Japan, Malaysia, Pakistan, South Korea, Taiwan, Thailand) were included in the final review (Table 1). Of these, anaemia prevalence, ESA treatment prevalence and iron treatment prevalence data were available in 73 studies (85%), 39 studies (45%) and 33 studies (38%), respectively. No studies reporting on the prevalence of HIF‐PHI use in patients with CKD in Asia were identified in this search.
FIGURE 1.
Flow diagram of study selection. Search conducted on May 17, 2023. * 2 cohorts included with 2 studies each, 1 reported anaemia outcomes and 1 reported anaemia treatment outcomes. ** Individual patient data for 6 studies, summary‐level data for 5 studies.
TABLE 1.
Baseline characteristics of all included studies pooled by country.
| Country | Included studies, n (ESKD a ) | Studies reporting the prevalence of outcome of interest, n | Participants, n | Female, % (SD) b | Age, years (SD) b | Diabetes, % (SD) b | HTN, % (SD) b | CVD, % (SD) b | Mean eGFR b , mL/min/1.73 m2 (SD) b , c | Mean Hb, g/L (SD) b | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Anaemia | ESA use | Iron use | ||||||||||
| Brunei | 2 e (2) | 1 | 1 | 0 | 881 | 49 | 53.8 | 79 | d | d | d | 111.0 |
| China | 28 (7) | 23 | 11 | 10 | 88 941 | 46.1 (10.1) | 57.0 (14.9) | 35.1 (27.7) | 64.0 (19.8) | 22.7 (17.4) | 60.5 (23.5) | 122.0 (13.9) |
| India | 6 (3) | 4 | 5 | 2 | 10 085 | 26.9 (8.2) | 48 (7.0) | 32.7 (19.2) | 71.6 (29.8) | 14.9 (9.8) | 40.5 | 91.7 (0.37) |
| Iran | 5 (4) | 5 | 1 | 1 | 16 700 | 44.3 (7.0) | 57.7 (7.1) | 49.5 (45.5) | 41.3 (10.1) | d | d | 119.0 (18.6) |
| Japan | 23 e (6) | 20 | 12 | 12 | 910 535 | 40.1 (12.7) | 63.8 (8.2) | 31.9 (16.9) | 72.3 (17.9) | 25.4 (29.4) | 51.8 (13.7) | 123.0 (11.6) |
| Malaysia | 4 (1) | 4 | 2 | 2 | 60 557 | 44.4 (6.2) | 61.2 (2.6) | 81.2 (26.7) | 83.1 (7.6) | 13.3 (4.3) | 27.8 | 106.0 (4.2) |
| Pakistan | 1 (0) | 1 | 0 | 0 | 1052 | 48.6 | d | 49.9 | 86.7 | 19.6 | d | d |
| South Korea | 7 (2) | 7 | 2 | 3 | 98 291 | 45.2 (6.9) | 53.1 (9.5) | 23.9 (17.9) | 40.7 (32.5) | 7.7 (6.3) | 60.3 (31.7) | 124.0 (21.1) |
| Taiwan | 9 (3) | 7 | 3 | 2 | 122 613 | 42.4 (11.2) | 60.7 (6.8) | 30.7 (19.3) | 56.2 (20.8) | 18.1 (11.5) | 52.5 (23.7) | 122.0 (23.0) |
| Thailand | 1 (1) | 1 | 1 | 1 | 32 466 | 5.9 | d | d | d | d | d | 101.0 |
| Overall | 86 (29) | 73 | 38 | 33 | 1 342 121 | 42.0 (11.8) | 58.8 (11.3) | 36.2 (25.1) | 63.8 (22.8) | 20.4 (20.8) | 54.9 (20.9) | 120.0 (15.9) |
Studies that only include participants with end‐stage kidney disease (ESKD) including those on haemodialysis or peritoneal dialysis, or kidney transplant recipients.
Overall mean and standard deviation reported when greater than 1 study was included in the analysis.
Mean estimated glomerular.
Not reported.
2 studies included from the same cohort, reporting different outcomes.
Overall, 42.0% of participants were female, and the mean age was 58.8 years. There was a wide range in the proportion of participants with diabetes mellitus (3.1%–100.0%), hypertension (11.5%–95.2%) and cardiovascular disease (1.5%–100.0%) across the studies. The mean eGFR was 55 mL/min/1.73 m2 (across studies included in “CKD all stages”), and the overall mean Hb was 120 g/L (129 g/L in “CKD all stages” studies, 106 g/L in “ESKD only” studies).
Twenty‐nine studies (34%) were conducted in ESKD cohorts. The majority of studies were from China and Japan (33% and 27%, respectively). There was high variability in the definition of anaemia, with 54 studies (63%) using definitions derived from guidelines such as KDIGO and the World Health Organisation (WHO) [10, 22]. Nine studies (10%) had a high risk of bias (Table S2).
3.2. Prevalence of Anaemia
Of the 26 countries in Asia, data on anaemia prevalence were available for 10 (Figure 2). The estimated prevalence of anaemia in individuals with CKD across these 10 countries varied widely within and across countries (overall pooled prevalence: 42% [95% CI 33%–52%]; I 2 > 99%; Figure 2). Among studies that included individuals with all stages of CKD (“CKD all stages”), pooled anaemia prevalence ranged from 12% (95% CI 2%–50%) in South Korea to 57% (95% CI 35%–76%) in Malaysia. The overall prevalence of anaemia among studies of individuals with ESKD only was higher than that in the CKD all stages group, ranging from 21% (95% CI 18%–24%) in Brunei to 96% (95% CI 96%–96%) in Taiwan.
FIGURE 2.
Prevalence of anaemia in chronic kidney disease in Asia, pooled by country and CKD stage. I 2 values displayed as a percentage and are not applicable for countries with only one study included in the analysis. CI, confidence interval; CKD, chronic kidney disease; ESKD, end‐stage kidney disease; N, number.
In subgroup analyses (performed across countries), the estimated pooled prevalence of anaemia increased by worsening CKD stage (pooled prevalence in stages 1 and 5 being 12% and 80%; p for trend < 0.001; Figure 3). While the data on anaemia prevalence by CKD stage were limited within each country, the pattern appeared consistent (Figure S1). There was no evidence of differences in anaemia prevalence according to age (p = 0.16), sex (p = 0.72), cardiovascular disease status (p = 0.11) or anaemia definition used (p = 0.67); however, the prevalence was double, or almost so, in studies with a high proportion of participants with diabetes or hypertension, compared to those with lower proportions (p for heterogeneity = 0.03 in each case; Figure 4).
FIGURE 3.
Prevalence of anaemia and anaemia treatment in chronic kidney disease in Asia, by CKD stage. I 2 displayed as a percentage. CI, confidence interval; ESA, erythropoietin‐stimulating agent; N, number.
FIGURE 4.
Subgroup analysis of the prevalence of anaemia in chronic kidney disease in Asia according to baseline characteristics. *p‐value for heterogeneity between subgroups. ** Anaemia defined based on KDIGO guidelines (male: Hb < 130 g/L, female: Hb < 120 g/L). CI, confidence interval; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; N, number.
3.3. Prevalence of Anaemia Treatment
Data on anaemia treatment, particularly in NDD‐CKD cohorts, were limited and heterogeneous (ESA I 2 > 99%; iron I 2 > 99%) (Figure S2A,B). The overall prevalence of ESA therapy was 40% (95% CI 24%–58%) and 11% (95% CI 5%–24%) in “CKD all stages” and 79% (95% CI 71%–84%) in “ESKD only”. In comparison, the overall utilisation of iron was lower at 21% (95% CI 14%–31%) and 11% (95% CI 7%–17%) in “CKD all stages” and 43% (95% CI 30%–58%) in “ESKD only”. The data on anaemia treatment patterns particularly for early stages of CKD were sparse; however, the trends were consistent with the prevalence of anaemia. The pooled prevalence of ESA therapy and iron supplementation for CKD stages 1 and 2 combined with stage 5, irrespective of country, was 0.3% to 69% and 3% to 37%, respectively (p for trend < 0.001; Figure 3).
4. Discussion
In this review, we report the prevalence of anaemia and its treatment patterns among people with CKD using the best available data across Asia. Our findings, based on data from 10 countries/regions, suggest a high prevalence of anaemia in Asian people with CKD, with significant variability in prevalence both between countries and between individual studies within the same country. We estimated the overall prevalence of anaemia in adult CKD patients to be 27%, ranging between 12% in South Korea and 57% in Malaysia. As expected, the prevalence of anaemia and requirements for ESA or iron therapy increased progressively with more advanced stages of CKD and peaked in those with ESKD. The prevalence of anaemia in patients on maintenance dialysis or kidney transplant recipients was between 21% in Brunei and 96% in Taiwan, with an overall estimate of 79%. There were no available prevalence data on HIF‐PHI therapy in the region.
Anaemia is a potentially modifiable risk factor that accelerates the progression of CKD, increases mortality and hospitalisation in people on maintenance dialysis and contributes to the cost of CKD treatment [23, 24, 25, 26, 27]. Understanding the burden of anaemia in CKD and optimising its treatment is therefore important for improving outcomes and reducing costs of care. A review of studies conducted in Japan reported that approximately 32% of people with stage 3–5 CKD were anaemic, with highly variable prevalence estimates ranging between 0% and 95% depending on the severity of CKD and the definition of anaemia used [28]. Our current study substantially expands these findings to broader regions of Asia (10 countries encompassing 79.9% of the population in the Asia‐Pacific region based on estimates from 2021 [29]), confirming comparable variability in the prevalence of anaemia and its treatment patterns across these regions. In comparison, the United States National Health and Nutrition Examination Survey found the prevalence of anaemia to be 15.4% in people with CKD, ranging between 8.4% and 53.4% in stage 1 and stage 5 CKD, respectively [30]. A separate cross‐sectional survey in 5222 subjects with pre‐dialysis CKD in the United States conversely showed much higher rates of anaemia of 47.7% overall and up to 75.5% in those with an eGFR < 15 mL/min/1.73m2 [31], which was more consistent with our findings in Asia. In Europe, the prevalence of anaemia in CKD was also found to differ significantly between studies, ranging between 12.8% and 61.5% [32].
Several factors may explain the observed variability in anaemia prevalence. Firstly, the baseline characteristics of the study population may play a role. Our subgroup analyses suggest a higher prevalence of anaemia in populations with a greater proportion of comorbid diabetes and hypertension. These findings support existing observational data that diabetes mellitus may be associated with lower haemoglobin concentrations in CKD [33] and that the global prevalence of anaemia in patients with CKD and comorbid diabetes has been increasing by 1.3% annually [34]. Secondly, we found substantial variability in how anaemia was defined across the individual studies. Many studies used the WHO or KDIGO definition (Hb < 130 g/L for men and Hb < 120 g/L for non‐pregnant women), some used CKD‐ or country‐specific thresholds and others defined anaemia based on lower haemoglobin levels (e.g., Hb < 100 g/L) but included the use of ESA therapy. Whilst our analysis suggests that the anaemia prevalence estimates are similar across different definitions, the complexities of defining anaemia in CKD including the implications of anaemia treatment prevail. For example, haemoglobin treatment targets for ESA use in CKD are lower than those recommended for the general population, as ESA therapy is associated with an increased risk of stroke and thrombosis at higher haemoglobin levels [35].
Our findings also provide insights into the current anaemia treatment practices in Asia. International guidelines recommend maintaining haemoglobin between 100 and 120 g/dL in adults with CKD and commencement of ESA in those with Hb < 100 g/L [36, 37]. Overall, we observed that the extent of ESA use generally corresponded with the magnitude of anaemia prevalence (overall and by CKD stage), suggesting broad alignment with clinical guidelines related to anaemia management; however, data were sparse. We also found the overall use of ESA therapy in the Asia‐Pacific region was slightly higher than documented global estimates in NDD‐CKD populations. An International Network of CKD Cohort Studies (iNET‐CKD) cross‐sectional study reported that 8.4% of the 58 613 participants with NDD‐CKD were receiving ESA therapy and that this ranged widely from 0% to 24.9% across cohorts worldwide [33]. Conversely, we found the prevalence of ESA therapy in patients with ESKD in Asia to be lower than in the rest of the world. The Phase III Dialysis Outcomes and Practice Patterns Study (DOPPS) reported that whilst the proportion of dialysis patients receiving ESA therapy was 91.2% in the United States, 94.2% in Sweden and 90.7% in Australia and New Zealand, it was lowest in Japan at 82.6% [38]. The data on iron therapy were even more limited, particularly in the earlier stages of CKD, despite the well‐recognised risk of both absolute and functional iron deficiency in CKD [39]. Overall, we found that the proportion of patients receiving iron therapy was lower than the prevalence of anaemia or use of ESA, indicating that it is underutilised in CKD particularly in dialysis patients, even more so than in other parts of the world [40]. In the Phase IV DOPPS study, the overall use of intravenous iron was 71%, with low rates reported in Japan at 36% compared to 70% in Australia and New Zealand and 90% in Belgium [41]. As seen with the patterns of anaemia and ESA therapy, we also found that the use of iron increased with advancing CKD stage—a finding observed despite the absence of an association between the prevalence of iron deficiency and kidney disease severity in patients with CKD stages 3–5 [40, 42]. These incongruencies reflect the challenges in the diagnosis and management of iron deficiency anaemia in CKD, including unreliable biomarkers for estimating iron stores and limited data on the clinical benefits and therapeutic targets of iron administration, particularly in NDD‐CKD [43]. Country‐specific prescribing practices, financial reimbursement incentives and treatment availability have been suggested as contributing factors to the differences in anaemia management across countries and regions [41, 44]. However, no comprehensive studies have been conducted to confirm this in Asia outside of Japan [44]. HIF stabilisers are an evolving option in the management of anaemia in CKD; however, data on the patterns of its use in patients with CKD in Asia are lacking.
A key finding of our study was the lack of systematic data collection and recording, especially for NDD‐CKD patients across Asia, including in high‐income countries. We noted significant heterogeneity within all subgroup analyses with I 2 values generally greater than 95%. There is a paucity of reporting of anaemia, particularly in the stages 1 and 2 CKD population, and little evidence around outcomes and treatment targets. The population of patients with NDD‐CKD is far larger than the subset receiving maintenance dialysis [41]; hence, robust prevalence and treatment data are important to develop proactive health policies for appropriate management of anaemia in CKD.
To our knowledge, this is the first comprehensive report on the regional prevalence of anaemia among CKD patients in Asia. We obtained unpublished contemporary data from several countries in Asia, representing a large portion of the regional population, using a comprehensive and systematic approach. However, this review has some limitations, mainly due to limited data availability and the variability in data quality and reporting (e.g., definitions used to define anaemia) across the included studies. The distribution of available data throughout the region was also unequal with a high representation from Japan and limited data from other countries such as Brunei and Pakistan, which may influence the overall estimate. Furthermore, our ability to analyse the treatment of anaemia was restricted by the fact that most studies, especially non‐dialysis studies, did not provide adequate information on treatment. Data on the impact of anaemia on clinical outcomes were also lacking. Conducting analyses based on summary‐level data also limited our capacity to fully investigate the relationships between anaemia prevalence (and its treatment) and patient characteristics, such as sex, age, pregnancy, altitude, concurrent medications and smoking status.
5. Conclusion
Our review reveals high, but widely variable, anaemia prevalence among people in Asia with CKD and ESKD. Prevalence data are lacking in large parts of the region, with variable definitions of anaemia and CKD in use. Although ESA and various other treatments are available, accurate information on anaemia burden and its treatment patterns is sparse in Asia. More data are required to understand the impact of anaemia on outcomes, and the patient‐related, as well as health systems, factors that influence treatment practice so that appropriate cost‐effective locally relevant treatment strategies to manage anaemia in CKD in Asia can be developed.
Author Contribrutions
D.K., J.L., T.T., T.L., V.J., M.G.W. and M.J. were responsible for study concept design, data collection, analysis, interpretation and manuscript preparation. All authors were involved in critical revision of the analyses, interpretation of the findings and the editing of manuscripts. The corresponding author (MJ) had full access to all data in the study and took responsibility for the integrity of the data and accuracy of the analysis and final manuscript. This study included data from the ARC. The Steering Committee members for ARC include Vivekanand Jha (India‐Chair), Vlado Perkovic (Australia‐Deputy Chair), Atsushi Wada (Japan), Daiki Inaguma (Japan), Heide Stirnadel‐Farrant (United Kingdom), Helen Monaghan (Australia), Ho Jun Chin (South Korea), Hong Zhang (China), Hooi Lai Seong (Malaysia), Ikuto Masakane (Japan), Kamal Shah (India), Kazuhiko Tsuruya (Japan), Kearkiat Praditpornsilpa (Thailand), Kunihiro Matsushita (USA), Kunitoshi Iseki (Japan), Luxia Zhang (China), Mariko Miyazaki (Japan), Mark Woodward (Australia/UK), Masafumi Fukagawa (Japan), Ming‐Yen Lin (Taiwan), Rajasekara Chakravarthi (India), Satoshi Ogata (Japan), Shang‐Jyh Hwang (Taiwan), Takayuki Hamano (Japan), Thaminda Liyanage (Australia), Toshiharu Ninomiya (Japan), Yoshinari Yasuda (Japan), Young‐Hwan Hwang (Korea) and Zuo Li (China).
Conflicts of Interest
DK, TL, LSH, MYL and KI have nothing to disclose. JL has received travel fees from Baxter and Amgen outside the submitted work. TT has received research funding from Mitsubishi Tanabe Pharma Corporation and speaker fees from AstraZeneca. MW has received fees from Amgen and Freeline outside the submitted work. KM received personal fees from Akebia and Kyowa Kirin outside of the submitted work. VJ has received grant funding from GSK, Baxter Healthcare and Biocon and honoraria from Bayer, AstraZeneca, Novartis, Vera, Chinook, Otsuka, Omeros, Boehringer Ingelheim, NephroPlus and Zydus Cadilla, outside the submitted work. MGW has received fees for advisory boards, Steering Committee roles, or scientific presentations from Travere, Baxter, Amgen, Abbvie, Chinook, Dimerix, Ostuka, GlaxoSmithKline and CSL‐Behring, outside the submitted work. MJ is responsible for research projects that have received research funding from Boehringer Ingelheim and Eli Lilly Alliance outside of the submitted work.
Supporting information
File S1. Supporting Information.
Appendix S1. Search strategy.
Appendix S2. Modified version of the Newcastle‐Ottawa Quality Assessment Scale for cohort studies.
Table S1. Summary of all included studies.
Table S2. Risk of bias assessment.
Figure S1. Prevalence of anaemia in chronic kidney disease, by CKD stage, across different countries in Asia.
Figure S2. Prevalence of anaemia treatment in chronic kidney disease in Asia, pooled by country and CKD stage.
Acknowledgements
Funding for this study was provided by GSK. GSK was provided with the opportunity to review a preliminary version of this publication for factual accuracy; however, the authors were solely responsible for the final content and interpretation. MJ was supported by the Scientia Program at the Faculty of Medicine and Health, UNSW Sydney, Australia. Open access publishing facilitated by University of New South Wales, as part of the Wiley ‐ University of New South Wales agreement via the Council of Australian University Librarians.
Funding: This work was supported by GlaxoSmithKline.
Data Availability Statement
All data relevant to the study are included in the article or uploaded as online supplemental information. All data generated or analysed during this study are included in this article and its online supplemental information files. Restrictions apply to the availability of individual participant data collected and used by agreement of the Asian Renal Collaboration for the current study and so are not publicly available.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
File S1. Supporting Information.
Appendix S1. Search strategy.
Appendix S2. Modified version of the Newcastle‐Ottawa Quality Assessment Scale for cohort studies.
Table S1. Summary of all included studies.
Table S2. Risk of bias assessment.
Figure S1. Prevalence of anaemia in chronic kidney disease, by CKD stage, across different countries in Asia.
Figure S2. Prevalence of anaemia treatment in chronic kidney disease in Asia, pooled by country and CKD stage.
Data Availability Statement
All data relevant to the study are included in the article or uploaded as online supplemental information. All data generated or analysed during this study are included in this article and its online supplemental information files. Restrictions apply to the availability of individual participant data collected and used by agreement of the Asian Renal Collaboration for the current study and so are not publicly available.