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The impact of diabetes on economic costs in dialysis patients: experiences in Taiwan
Diabetes Research and Clinical Practice 54 Suppl. 1 (2001) S47– S54 www.elsevier.com/locate/diabres
The impact of diabetes on economic costs in dialysis patients: experiences in Taiwan Wu-Chang Yang a,*, Shang-Jyh Hwang b, Shoou-Shan Chiang c, Hsueh-Fen Chen d, Shih-Tzer Tsai e a Di6ision of Nephrology, Department of Medicine, School of Medicine, Taipei Veterans General Hospital and National Yang-Ming Uni6ersity, No. 201, Shih-Pai Road, Section 2, Taipei 11217 Taiwan, ROC b Department of Medicine, Kaohsiung Municipal Hsio-Kang Hospital, Kaohsiung Medical Uni6ersity, Kaohsiung, Taiwan, ROC c Di6ision of Nephrology, Hsing-Kong Woo Hou-Su Memorial Hospital, Taipei, Taiwan, ROC d Di6ision of Performance Management, Taipei Veterans General Hospital, Taipei, Taiwan, ROC e Di6ision of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
Abstract Diabetes mellitus carries a great burden on healthcare costs due to its growing population and high co-morbidity. This adverse effect sustains even when patients develop end-stage renal disease (ESRD). We here present data showing the effect of diabetes on economic costs in dialysis therapy in Taiwan. As of the end of 1997, we have 22 027 ESRD patients with a prevalence and incidence rate of 1013 and 253 per million populations, respectively. Diabetic nephropathy is the second most common cause of the underlying renal diseases, but accounts for 24.8% of the prevalent patients and 35.9% of the incident cases. The diabetic patients engendered 11.8% more expense for care of dialysis than the non-diabetic patients (US$26 988 vs. US$24 146 per patient-year). Higher inpatient cost mainly account for the difference. As compared to non-diabetic patients, the diabetic patients had 3.5 times more inpatients costs (US$1325 vs. US$4677 per patient-year), and higher proportion of inpatient-to-annualized cost ratio (5.5 vs. 17.3%) resulting from their more frequent hospitalization (0.59 vs. 1.13 times per patient-year) and longer hospital stay (6.7 vs. 18.9 days per patient-year). The major causes responsible for a more frequent hospitalization were cardiovascular disease, poorly controlled hyperglycemia, sepsis and failure of vascular access. The annualized costs for care of dialysis patients in Taiwan, including inpatient and outpatient costs, averaged US$25 576 per patient-year. This value is approximately half of that in most of the western countries and Japan. Thus, a more cost-effective way to achieve savings is to reduce the high incidence rate of dialysis population and to maximize the quality of dialysis treatment for avoiding hospitalization. Recent studies had shown that tight blood pressure control, intensive glycemic control, and use of angiotensin converting enzyme inhibitors in diabetic patients significantly reduced not only the rate of progressive renal failure, but also substantially reduced the cost of complications and led to higher cost effectiveness. Once diabetic patients reach stage of ESRD, an optimized pre-ESRD care and consideration of kidney transplantation are essential in terms of better patient survival and cost savings. © 2001 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Diabetes; Economic cost; Dialysis
* Corresponding author. Tel.: + 886-2-2875-7517; fax: + 886-2-2873-4866. E-mail address: [email protected] (W.-C. Yang). 0168-8227/01/$ - see front matter © 2001 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 1 6 8 - 8 2 2 7 ( 0 1 ) 0 0 3 0 9 - 6
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1. Introduction Diabetes mellitus carries a great impact on morbidity and mortality, when patients develop renal failure resulting from diabetic nephropathy [1 –5]. Patients with diabetic nephropathy have a significant increase in the incidence of coronary artery disease (CAD), congestive heart failure (CHF), peripheral vascular diseases (PVD), orthostatic hypotension, hyperlipidemia, and mortality than diabetic patients without renal involvement. These adverse prognoses sustain or even aggravate, when patients develop end-stage renal disease (ESRD) and are being treated with dialysis. The overall prevalence of renal involvement is around 30–35% in both Type 1 and 2 diabetes [6]. It was previously believed that the risk of renal involvement was lower in Type 2 diabetes [7]. However, Ritz et al. recently demonstrated that the cumulative incidence of diabetic nephropathy was probably similar between Type 1 and 2 diabetes if the patients’ life spans are long enough [8,9]. Because the diabetic population has dramatically increased over the past decade, it can be foreseen that we will see more patients with diabetic nephropathy than before [10]. Taken together, it is expected that a greater number of patients with diabetic nephropathy would progress into the ESRD program and lead to a tremendous impact on socio-economic costs in dialysis therapy. Despite the fact that Bureau of National Health Insurance (BNHI), DOH spent 6.0% of the fiscal year budget on the reimbursement of dialysis therapy, no report has addressed this issue in this country. In this article, we tried to review the current status of ESRD patients due to diabetic nephropathy and the costs engendered for care of these patients in Taiwan. The data we collected might identify, where costs are encountered for diabetic dialysis patients, so that potential strategies to enhance a cost-effective renal care can be developed.
2. Current status of patients with diabetic nephropathy receiving dialysis therapy in Taiwan In Taiwan, a yearly on-site National Dialysis
Surveillance Program was launched in 1987. Designed by Taiwan Society of Nephrology (TSN), this program was funded and endorsed by Department of Health, ROC. The prevalent patients’ data were collected at the end of each fiscal year. As of 31 December 1997, there were 22 027 ESRD patients; 94% of them received hemodialysis and the other 6% received peritoneal dialysis as their renal replacement therapy [11]. The prevalence and incidence rate of ESRD patients were, 1013 and 252 per million populations (pmp) respectively. Of the past 7 years, the population of ESRD patients markedly increased as compared to those in fiscal year 1990, while the prevalence and incidence rate were 494 and 141 pmp, respectively. The mean age of dialysis patients was 4.1 years older, and the proportion of incident diabetic population increased by 8.9%. The underlying cause of these prevalent ESRD patients was mainly chronic glomerulonephritis, comprised of 49.4% of the total patients. Diabetic nephropathy was the second most common cause. Its proportion was 20.3% in year 1990 and gradually increased to 24.8% in year 1997 (Fig. 1). Nevertheless, the proportion of diabetic nephropathy in newly diagnosed ESRD patients markedly increased from 27.0% in year 1990 to 35.9% in year 1997. Such a high incidence rate for diabetic ESRD patients resembles that found in western countries and Japan in Asia. The number of diabetic population in ESRD patients reported by TSN is compatible with the recent findings of epidemiological studies in diabetes and its complications in Taiwan. Chou et al. recently reported that the age-adjusted prevalence rate of diabetes was around 4.0% in a communitybase population survey [12,13]. According to the 1998 BNHI database, however, only 60% of diabetic patients had been followed or treated somewhere. Very recently, Chuang et al. reported that the long-term complication of diabetes manifested with proteinuria and ESRD was respectively, 17 and 1% of those diabetic patients being followed in a Diabcare-Taiwan study [14]. Based on a general population of 21.7 million in Taiwan, we expected to have 5200 diabetic ESRD patients in year 1997, a number very close to that reported
W.-C. Yang et al. / Diabetes Research and Clinical Practice 54 Suppl. 1 (2001) S47– S54
by TSN. Taken together, it might be reasonable to assume that the prevalence of diabetes is 4.0% of the general population in Taiwan, and about 1% of those diagnosed diabetic patients will progress to ESRD in the long run.
3. Medical cost expenditure for dialysis therapy in diabetic patients The total reimbursement for dialysis and erythropoietin therapy was 528 million US dollars (approximate to 15.85 billion NT dollars) in year 1999, which had driven 5.87% of BNHI fiscal year budget [15]. To reduce the cost and that for administration on reimbursement of erythropoietin therapy, the BNHI had adopted a capitation policy starting from July 1996, in which the reimbursement was US$137 per dialysis session (ap-
Fig. 1. The prevalence (panel A) and incidence rate (panel B) of the underlying causes of dialysis patients in Taiwan. Data were collected by TSN as of 31 December 1997.
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proximate to NT$4100). The reimbursement rate was fixed and included the cost for all supplies, overhead, erythropoietin, renal anemia-related blood transfusion, medication, monthly laboratory tests, nursing, and physician fee. Despite the stability of the composite rate, the total cost for care of dialysis patients continues to rise. We thus recently conducted a multi-center survey to determine, where costs were encountered, and to investigate the impact of diabetes on these medical costs. Three medical centers including one government-based university hospital (Taipei Veterans General Hospital), one private university hospital (Kaohsiung Medical University Hospital) and one private community hospital (Hsing-Kong Woo Hou-Su Memorial Hospital) participated in this study. Because the medical costs are the highest within the first year after the initiation of dialysis, only patients who had received outpatient dialysis therapy for at least 1 year were enrolled. Of the total 513 patients enrolled, 106-paired diabetic and non-diabetic patients were selected for this study, with sex, age, and duration of dialysis matched. In these three hospitals, all inpatient and outpatient encounters were recorded in a clinical and financial data repository. Inpatient costs included all costs occurring while patients were staying in the hospital, and outpatient cost occurred, when patients were not staying in the hospitals. The systems permit retrieval of patient records by procedures or laboratory tests and will recover all encounters with a given patient between specific dates. Costs for categories were then normalized to a 12-month period to give annualized costs per patient-year at risk. Our results disclosed that the annualized costs for care of dialysis patients, including all inpatient and outpatient costs, averaged US$25 576 per patient-year. The ratio of inpatient-to-outpatient reimbursement was 11.8:88.2% (Table 1). Overall, the diabetic patients engendered 11.8% more expense per patient-year than the non-diabetic patients (Fig. 2). Higher inpatient costs, as well as slightly higher costs for outpatient clinic, accounted for the difference.
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Table 1 The annualized medical cost per patient-year for care of diabetic vs. non-diabetic ESRD patients in Taiwan Medical cost
DM
non-DM
All patients
Total cost (US$/patient-year)
26 988
24 146
25 576
Outpatient (US$/patient-year) Dialysis and EPO Other clinic
22 311 19 841 (88.9%) 2470 (11.1%)
22 820 21 209 (92.9%) 1611 (7.1%)
22 564 20 521 (90.9%) 2043 (9.1%)
4677 1093 (23.4%) 3584 (76.6%)
1325 409 (30.9%) 916 (69.1%)
3012 753 (25.0%) 2259 (75.0%)
Hospitalization (US$/patient-year) Dialysis and EPO Others
4. Costs and causes of hospitalization in diabetic patients The inpatient costs in diabetic patients (US$4677 per patient-year) was 3.5 times more than that engendered in non-diabetic patients (US$1325 per patient-year). It represented 17.3 vs. 5.5% of the annualized cost in diabetic and nondiabetic patients, respectively (Fig. 2). The higher inpatient cost of diabetic patients can be precisely reflected in their more frequent hospitalization and longer hospital stay (Fig. 3). The average frequency of hospitalization was 1.13 times per patient-year in diabetic patients, as compared to 0.59 times per patient-year in non-diabetic patients. Fig. 4 showed that the major causes responsible for a more frequent hospitalization in diabetic patients were CAD, CHF, poorly controlled hyperglycemia, PVD, sepsis, failure of vascular access, retinopathy and cataract. The average hospital stay was 18.9 days in diabetic patients as opposed to 6.7 days per patient-year in non-diabetic patients (Fig. 3). In a 2-year historically prospective follow-up, there is a 2.15 times higher mortality in diabetic than non-diabetic patients (26.1 vs. 12.1%, P B 0.02).
5. Discussion and conclusions In healthcare economics, all countries allot a significant share of their healthcare budget to dialysis therapy for ESRD patients [10,16– 18]. To control healthcare costs in this population, the Taiwan BNHI have made several efforts over the
past years, most notably the establishment of a capitation policy for the reimbursement of dialysis therapy at a fixed composite rate. Nevertheless, the total costs for the dialysis program keep rising owing to the growing number of ESRD patients, especially in the diabetic and aging population [11,15]. According to an international comparison on healthcare systems and ESRD therapies [18], the average annualized costs engendered by dialysis therapy in Taiwan (US$21 274 per patientyear) is only approximately half of that in Japan and western countries except Italy. Even if the costs are adjusted for GDP, dialysis patients still engendered less expense in Taiwan. Thus, a more cost-efficient way to achieve savings is to reduce the high incidence rate of dialysis population by strategies for preventing and delaying the progression of chronic renal failure, and to maximize the quality of dialysis treatment for avoiding hospitalization. With an incidence rate of 252 ppm, we expect to have 6000 new patients accepted into the dialysis program per year in Taiwan. If the progression of renal failure can be retarded by at least 1 year before ESRD occurs in these patients, the costs engendered for dialysis therapy can be reduced by 153 million US dollars a year, about 24% of BNHI fiscal year budget. Due to its proportion of 35.9% in incident cases, we will see one diabetic patient for every three new dialysis patients (Fig. 1). Thus, every effort should be made for early detection and management of renal involvement in diabetics [9,19,20]. Recent studies had shown that tight control of blood pressure [21], intensive blood glucose control
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Fig. 2. The annualized medical cost per patient-year (panel A) and categories of cost (panel B) for care of diabetic vs. non-diabetic ESRD patients. Diabetic patients engendered more expense per year mainly due to a higher inpatient cost.
[22,23], and use of angiotensin converting enzyme (ACE) inhibitors [24– 26] in diabetic patients significantly reduced not only the rate of progressive renal failure, but also substantially reduced the cost of complications and led to higher cost effectiveness. Other interventional treatment modalities including dietary protein restriction [27,28], lipid lowering agents [29,30], and intensified intervention [31,32] with various combination including dietary protein restriction, anti-hypertensive therapy with ACE inhibitors, intensive glycemic control, and hypolipidemic agents all have evidences demonstrating a renoprotective effect in these patients, and thereby, may provide an advantageous cost-benefit treatment. When diabetic patients progress to ESRD and start renal replacement therapy, their morbidity and survival continue to be poor owing to their high co-morbidity mainly from cardiovascular causes [33–35]. Similar findings are also found in our study showing a higher frequency of hospitalization and a longer hospital stay in diabetic patients, that engendered higher inpatient costs and consequent higher annualized costs (Figs. 3 and 4). Noteworthy is that late referral to nephrologist prior to the initiation of dialysis is associated with increased metabolic abnormalities, increased short- and long-term mortality, delayed selection of dialysis modality, delayed placement of permanent access, prolonged hospitalization, and increased costs [34,36– 40]. The diabetic patients usually require dialysis earlier than the nondiabetic patients, and prophylactic vascular access
should be established, when their glomerular filtration rate is B 25 ml/min and hemodialysis is to be chosen for future renal replacement therapy. Unfortunately, many diabetic patients receiving their first dialysis had unfavorably clinical features similar to the findings of Chantrel et al. [34]. In that study, 63% of the diabetic patients had late referral, when starting dialysis. Most of the patients were over-hydrated, presented high blood pressure, had cardiovascular diseases, and necessitated temporary jugular or sub-clavian catheters for emergent dialysis, as a consequence, carrying a high risk of complications, such as hematoma, infection, and thrombosis. Access-related problems had been reported to account for 48% of all hospitalization [41]. Presence of diabetes can be a significantly poor predictor for primary and secondary success of vascular access [42]. Consistent with this notion is that our data showing a higher
Fig. 3. The impact of diabetes on frequency of hospitalization and hospital days per patient-year in diabetic vs. non-diabetic dialysis patient.
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Fig. 4. The causes of hospitalization in diabetic vs. non-diabetic dialysis patients. CAD: coronary artery disease; CHF: congestive heart failure; PVD: peripheral vascular diseases; Vascular access: failure of vascular access; and ANS dysfunction: autonomous nervous system dysfunction.
rate of failure of vascular access and access-related infections leading to a higher inpatient costs in diabetic patients (Fig. 4). In summary, diabetes has become the most common cause of new patients requiring renal replacement therapy, and consequently, incurring a tremendous burden on economic costs due to the growing number of diabetic population and its associated high co-morbidity. Once overt diabetic nephropathy develops, vigorous management should be given to provide a cost-effective care, including tight blood pressure control, intensive glycemic control, use of ACE inhibitors/A-II receptor antagonists, administration of lipid-lowering agents, timely placement of vascular access, and correction of renal anemia. When patients reach stage of ESRD, kidney transplantation should be considered in terms of patient survival and cost savings [43,44]. An interdisciplinary care is essential to accomplish such a purpose in the whole clinical spectrum of diabetic nephropathy. Acknowledgements The study was supported by the research grants from Bristol-Meyer Squibb Co. Taiwan and Ching-Mei Paper Co. Ltd. We also thank Ms Hui-Mei Lin and Ms Keri Yang for their helpful preparations of this manuscript.
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[25] L. Garattini, M. Brunetti, F. Salvioni, M. Barosi, Economic evaluation of ACE inhibitor treatment of nephropathy in patients with insulin-dependent diabetes mellitus in Italy, Pharmacoeconomics 12 (1997) 67 – 75. [26] W.F. Clark, D.N. Churchill, L. Forwell, G. Macdonald, S. Foster, To pay or not to pay? A decision and cost-utility analysis of angiotensin-converting-enzyme inhibitor therapy for diabetic nephropathy, CMAJ 162 (2000) 195 – 198. [27] J.D. Walker, J.J. Bending, R.A. Dodds, et al., Restriction of dietary protein and progression of renal failure in diabetic nephropathy, Lancet 2 (1989) 1411 – 1415. [28] K. Zeller, E. Whittaker, L. Sullivan, P. Raskin, H.R. Jacobson, Effect of restricting dietary protein on the progression of renal failure in patients with insulin-dependent diabetes mellitus, N. Engl. J. Med. 324 (1991) 78 – 84. [29] A.S. Krolewski, J.H. Warram, A.R. Christlieb, Hypercholesterolemia — a determinant of renal function loss and deaths in IDDM patients with nephropathy, Kidney Int. 45 (1994) S125 – S131. [30] G. Tonolo, M. Ciccarese, P. Brizzi, et al., Reduction of albumin excretion rate in normotensive microalbuminuric type 2 diabetic patients during long-term simvastatin treatment, Diabetes Care 20 (1997) 1891 – 1895. [31] A. Manto, P. Cotroneo, G. Marra, et al., Effect of intensive treatment on diabetic nephropathy in patients with type I diabetes, Kidney Int. 47 (1995) 231 – 235. [32] P. Gaede, P. Vedel, H.H. Parving, O. Pedersen, Intensified multifactorial intervention in patients with type 2 diabetes mellitus and microalbuminuria: the Steno type 2 randomised study, Lancet 353 (1999) 617 – 622. [33] E. Ritz, M. Koch, D. Fliser, V. Schwenger, How can we improve prognosis in diabetic patients with end-stage renal disease?, Diabetes Care 22 (Suppl 2) (1999) B80 – B83. [34] F. Chantrel, I. Enache, M. Bouiller, et al., Abysmal prognosis of patients with type 2 diabetes entering dialysis, Nephrol. Dial. Transplant 14 (1999) 129 – 136. [35] United States Renal Data System, 1999 Annual Data Report. Chapter VI: Causes of Death, Am. J. Kidney Dis. 34 Suppl 1 (1999) S87 – 94. [36] P.A. Ellis, V. Reddy, N. Bari, H.S. Cairns, Late referral of end-stage renal failure, QJM 91 (1998) 727 – 732. [37] O. Ifudu, M. Dawood, P. Homel, E.A. Friedman, Excess morbidity in patients starting uremia therapy without prior care by a nephrologist, Am. J. Kidney Dis. 28 (1996) 841 – 845. [38] A.V. Kshirsagar, S.L. Hogan, L. Mandelkehr, R.J. Falk, Length of stay and costs for hospitalized hemodialysis patients: nephrologists versus internists, J. Am. Soc. Nephrol. 11 (2000) 1526 – 1533. [39] B.J. Pereira, J.M. Burkart, T.F. Parker, Strategies for influencing outcomes in pre-ESRD and ESRD patients, Am. J. Kidney Dis. 32 (1998) S2 – S4. [40] R.J. Schmidt, J.R. Domico, M.I. Sorkin, G. Hobbs, Early referral and its impact on emergent first dialyses, health care costs, and outcome, Am. J. Kidney Dis. 32 (1998) 278 – 283.
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The impact of diabetes on economic costs in dialysis patients: experiences in Taiwan Wu-Chang Yang a,*, Shang-Jyh Hwang b, Shoou-Shan Chiang c, Hsueh-Fen Chen d, Shih-Tzer Tsai e a Di6ision of Nephrology, Department of Medicine, School of Medicine, Taipei Veterans General Hospital and National Yang-Ming Uni6ersity, No. 201, Shih-Pai Road, Section 2, Taipei 11217 Taiwan, ROC b Department of Medicine, Kaohsiung Municipal Hsio-Kang Hospital, Kaohsiung Medical Uni6ersity, Kaohsiung, Taiwan, ROC c Di6ision of Nephrology, Hsing-Kong Woo Hou-Su Memorial Hospital, Taipei, Taiwan, ROC d Di6ision of Performance Management, Taipei Veterans General Hospital, Taipei, Taiwan, ROC e Di6ision of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
Abstract Diabetes mellitus carries a great burden on healthcare costs due to its growing population and high co-morbidity. This adverse effect sustains even when patients develop end-stage renal disease (ESRD). We here present data showing the effect of diabetes on economic costs in dialysis therapy in Taiwan. As of the end of 1997, we have 22 027 ESRD patients with a prevalence and incidence rate of 1013 and 253 per million populations, respectively. Diabetic nephropathy is the second most common cause of the underlying renal diseases, but accounts for 24.8% of the prevalent patients and 35.9% of the incident cases. The diabetic patients engendered 11.8% more expense for care of dialysis than the non-diabetic patients (US$26 988 vs. US$24 146 per patient-year). Higher inpatient cost mainly account for the difference. As compared to non-diabetic patients, the diabetic patients had 3.5 times more inpatients costs (US$1325 vs. US$4677 per patient-year), and higher proportion of inpatient-to-annualized cost ratio (5.5 vs. 17.3%) resulting from their more frequent hospitalization (0.59 vs. 1.13 times per patient-year) and longer hospital stay (6.7 vs. 18.9 days per patient-year). The major causes responsible for a more frequent hospitalization were cardiovascular disease, poorly controlled hyperglycemia, sepsis and failure of vascular access. The annualized costs for care of dialysis patients in Taiwan, including inpatient and outpatient costs, averaged US$25 576 per patient-year. This value is approximately half of that in most of the western countries and Japan. Thus, a more cost-effective way to achieve savings is to reduce the high incidence rate of dialysis population and to maximize the quality of dialysis treatment for avoiding hospitalization. Recent studies had shown that tight blood pressure control, intensive glycemic control, and use of angiotensin converting enzyme inhibitors in diabetic patients significantly reduced not only the rate of progressive renal failure, but also substantially reduced the cost of complications and led to higher cost effectiveness. Once diabetic patients reach stage of ESRD, an optimized pre-ESRD care and consideration of kidney transplantation are essential in terms of better patient survival and cost savings. © 2001 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Diabetes; Economic cost; Dialysis
* Corresponding author. Tel.: + 886-2-2875-7517; fax: + 886-2-2873-4866. E-mail address: [email protected] (W.-C. Yang). 0168-8227/01/$ - see front matter © 2001 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 1 6 8 - 8 2 2 7 ( 0 1 ) 0 0 3 0 9 - 6
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W.-C. Yang et al. / Diabetes Research and Clinical Practice 54 Suppl. 1 (2001) S47– S54
1. Introduction Diabetes mellitus carries a great impact on morbidity and mortality, when patients develop renal failure resulting from diabetic nephropathy [1 –5]. Patients with diabetic nephropathy have a significant increase in the incidence of coronary artery disease (CAD), congestive heart failure (CHF), peripheral vascular diseases (PVD), orthostatic hypotension, hyperlipidemia, and mortality than diabetic patients without renal involvement. These adverse prognoses sustain or even aggravate, when patients develop end-stage renal disease (ESRD) and are being treated with dialysis. The overall prevalence of renal involvement is around 30–35% in both Type 1 and 2 diabetes [6]. It was previously believed that the risk of renal involvement was lower in Type 2 diabetes [7]. However, Ritz et al. recently demonstrated that the cumulative incidence of diabetic nephropathy was probably similar between Type 1 and 2 diabetes if the patients’ life spans are long enough [8,9]. Because the diabetic population has dramatically increased over the past decade, it can be foreseen that we will see more patients with diabetic nephropathy than before [10]. Taken together, it is expected that a greater number of patients with diabetic nephropathy would progress into the ESRD program and lead to a tremendous impact on socio-economic costs in dialysis therapy. Despite the fact that Bureau of National Health Insurance (BNHI), DOH spent 6.0% of the fiscal year budget on the reimbursement of dialysis therapy, no report has addressed this issue in this country. In this article, we tried to review the current status of ESRD patients due to diabetic nephropathy and the costs engendered for care of these patients in Taiwan. The data we collected might identify, where costs are encountered for diabetic dialysis patients, so that potential strategies to enhance a cost-effective renal care can be developed.
2. Current status of patients with diabetic nephropathy receiving dialysis therapy in Taiwan In Taiwan, a yearly on-site National Dialysis
Surveillance Program was launched in 1987. Designed by Taiwan Society of Nephrology (TSN), this program was funded and endorsed by Department of Health, ROC. The prevalent patients’ data were collected at the end of each fiscal year. As of 31 December 1997, there were 22 027 ESRD patients; 94% of them received hemodialysis and the other 6% received peritoneal dialysis as their renal replacement therapy [11]. The prevalence and incidence rate of ESRD patients were, 1013 and 252 per million populations (pmp) respectively. Of the past 7 years, the population of ESRD patients markedly increased as compared to those in fiscal year 1990, while the prevalence and incidence rate were 494 and 141 pmp, respectively. The mean age of dialysis patients was 4.1 years older, and the proportion of incident diabetic population increased by 8.9%. The underlying cause of these prevalent ESRD patients was mainly chronic glomerulonephritis, comprised of 49.4% of the total patients. Diabetic nephropathy was the second most common cause. Its proportion was 20.3% in year 1990 and gradually increased to 24.8% in year 1997 (Fig. 1). Nevertheless, the proportion of diabetic nephropathy in newly diagnosed ESRD patients markedly increased from 27.0% in year 1990 to 35.9% in year 1997. Such a high incidence rate for diabetic ESRD patients resembles that found in western countries and Japan in Asia. The number of diabetic population in ESRD patients reported by TSN is compatible with the recent findings of epidemiological studies in diabetes and its complications in Taiwan. Chou et al. recently reported that the age-adjusted prevalence rate of diabetes was around 4.0% in a communitybase population survey [12,13]. According to the 1998 BNHI database, however, only 60% of diabetic patients had been followed or treated somewhere. Very recently, Chuang et al. reported that the long-term complication of diabetes manifested with proteinuria and ESRD was respectively, 17 and 1% of those diabetic patients being followed in a Diabcare-Taiwan study [14]. Based on a general population of 21.7 million in Taiwan, we expected to have 5200 diabetic ESRD patients in year 1997, a number very close to that reported
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by TSN. Taken together, it might be reasonable to assume that the prevalence of diabetes is 4.0% of the general population in Taiwan, and about 1% of those diagnosed diabetic patients will progress to ESRD in the long run.
3. Medical cost expenditure for dialysis therapy in diabetic patients The total reimbursement for dialysis and erythropoietin therapy was 528 million US dollars (approximate to 15.85 billion NT dollars) in year 1999, which had driven 5.87% of BNHI fiscal year budget [15]. To reduce the cost and that for administration on reimbursement of erythropoietin therapy, the BNHI had adopted a capitation policy starting from July 1996, in which the reimbursement was US$137 per dialysis session (ap-
Fig. 1. The prevalence (panel A) and incidence rate (panel B) of the underlying causes of dialysis patients in Taiwan. Data were collected by TSN as of 31 December 1997.
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proximate to NT$4100). The reimbursement rate was fixed and included the cost for all supplies, overhead, erythropoietin, renal anemia-related blood transfusion, medication, monthly laboratory tests, nursing, and physician fee. Despite the stability of the composite rate, the total cost for care of dialysis patients continues to rise. We thus recently conducted a multi-center survey to determine, where costs were encountered, and to investigate the impact of diabetes on these medical costs. Three medical centers including one government-based university hospital (Taipei Veterans General Hospital), one private university hospital (Kaohsiung Medical University Hospital) and one private community hospital (Hsing-Kong Woo Hou-Su Memorial Hospital) participated in this study. Because the medical costs are the highest within the first year after the initiation of dialysis, only patients who had received outpatient dialysis therapy for at least 1 year were enrolled. Of the total 513 patients enrolled, 106-paired diabetic and non-diabetic patients were selected for this study, with sex, age, and duration of dialysis matched. In these three hospitals, all inpatient and outpatient encounters were recorded in a clinical and financial data repository. Inpatient costs included all costs occurring while patients were staying in the hospital, and outpatient cost occurred, when patients were not staying in the hospitals. The systems permit retrieval of patient records by procedures or laboratory tests and will recover all encounters with a given patient between specific dates. Costs for categories were then normalized to a 12-month period to give annualized costs per patient-year at risk. Our results disclosed that the annualized costs for care of dialysis patients, including all inpatient and outpatient costs, averaged US$25 576 per patient-year. The ratio of inpatient-to-outpatient reimbursement was 11.8:88.2% (Table 1). Overall, the diabetic patients engendered 11.8% more expense per patient-year than the non-diabetic patients (Fig. 2). Higher inpatient costs, as well as slightly higher costs for outpatient clinic, accounted for the difference.
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Table 1 The annualized medical cost per patient-year for care of diabetic vs. non-diabetic ESRD patients in Taiwan Medical cost
DM
non-DM
All patients
Total cost (US$/patient-year)
26 988
24 146
25 576
Outpatient (US$/patient-year) Dialysis and EPO Other clinic
22 311 19 841 (88.9%) 2470 (11.1%)
22 820 21 209 (92.9%) 1611 (7.1%)
22 564 20 521 (90.9%) 2043 (9.1%)
4677 1093 (23.4%) 3584 (76.6%)
1325 409 (30.9%) 916 (69.1%)
3012 753 (25.0%) 2259 (75.0%)
Hospitalization (US$/patient-year) Dialysis and EPO Others
4. Costs and causes of hospitalization in diabetic patients The inpatient costs in diabetic patients (US$4677 per patient-year) was 3.5 times more than that engendered in non-diabetic patients (US$1325 per patient-year). It represented 17.3 vs. 5.5% of the annualized cost in diabetic and nondiabetic patients, respectively (Fig. 2). The higher inpatient cost of diabetic patients can be precisely reflected in their more frequent hospitalization and longer hospital stay (Fig. 3). The average frequency of hospitalization was 1.13 times per patient-year in diabetic patients, as compared to 0.59 times per patient-year in non-diabetic patients. Fig. 4 showed that the major causes responsible for a more frequent hospitalization in diabetic patients were CAD, CHF, poorly controlled hyperglycemia, PVD, sepsis, failure of vascular access, retinopathy and cataract. The average hospital stay was 18.9 days in diabetic patients as opposed to 6.7 days per patient-year in non-diabetic patients (Fig. 3). In a 2-year historically prospective follow-up, there is a 2.15 times higher mortality in diabetic than non-diabetic patients (26.1 vs. 12.1%, P B 0.02).
5. Discussion and conclusions In healthcare economics, all countries allot a significant share of their healthcare budget to dialysis therapy for ESRD patients [10,16– 18]. To control healthcare costs in this population, the Taiwan BNHI have made several efforts over the
past years, most notably the establishment of a capitation policy for the reimbursement of dialysis therapy at a fixed composite rate. Nevertheless, the total costs for the dialysis program keep rising owing to the growing number of ESRD patients, especially in the diabetic and aging population [11,15]. According to an international comparison on healthcare systems and ESRD therapies [18], the average annualized costs engendered by dialysis therapy in Taiwan (US$21 274 per patientyear) is only approximately half of that in Japan and western countries except Italy. Even if the costs are adjusted for GDP, dialysis patients still engendered less expense in Taiwan. Thus, a more cost-efficient way to achieve savings is to reduce the high incidence rate of dialysis population by strategies for preventing and delaying the progression of chronic renal failure, and to maximize the quality of dialysis treatment for avoiding hospitalization. With an incidence rate of 252 ppm, we expect to have 6000 new patients accepted into the dialysis program per year in Taiwan. If the progression of renal failure can be retarded by at least 1 year before ESRD occurs in these patients, the costs engendered for dialysis therapy can be reduced by 153 million US dollars a year, about 24% of BNHI fiscal year budget. Due to its proportion of 35.9% in incident cases, we will see one diabetic patient for every three new dialysis patients (Fig. 1). Thus, every effort should be made for early detection and management of renal involvement in diabetics [9,19,20]. Recent studies had shown that tight control of blood pressure [21], intensive blood glucose control
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Fig. 2. The annualized medical cost per patient-year (panel A) and categories of cost (panel B) for care of diabetic vs. non-diabetic ESRD patients. Diabetic patients engendered more expense per year mainly due to a higher inpatient cost.
[22,23], and use of angiotensin converting enzyme (ACE) inhibitors [24– 26] in diabetic patients significantly reduced not only the rate of progressive renal failure, but also substantially reduced the cost of complications and led to higher cost effectiveness. Other interventional treatment modalities including dietary protein restriction [27,28], lipid lowering agents [29,30], and intensified intervention [31,32] with various combination including dietary protein restriction, anti-hypertensive therapy with ACE inhibitors, intensive glycemic control, and hypolipidemic agents all have evidences demonstrating a renoprotective effect in these patients, and thereby, may provide an advantageous cost-benefit treatment. When diabetic patients progress to ESRD and start renal replacement therapy, their morbidity and survival continue to be poor owing to their high co-morbidity mainly from cardiovascular causes [33–35]. Similar findings are also found in our study showing a higher frequency of hospitalization and a longer hospital stay in diabetic patients, that engendered higher inpatient costs and consequent higher annualized costs (Figs. 3 and 4). Noteworthy is that late referral to nephrologist prior to the initiation of dialysis is associated with increased metabolic abnormalities, increased short- and long-term mortality, delayed selection of dialysis modality, delayed placement of permanent access, prolonged hospitalization, and increased costs [34,36– 40]. The diabetic patients usually require dialysis earlier than the nondiabetic patients, and prophylactic vascular access
should be established, when their glomerular filtration rate is B 25 ml/min and hemodialysis is to be chosen for future renal replacement therapy. Unfortunately, many diabetic patients receiving their first dialysis had unfavorably clinical features similar to the findings of Chantrel et al. [34]. In that study, 63% of the diabetic patients had late referral, when starting dialysis. Most of the patients were over-hydrated, presented high blood pressure, had cardiovascular diseases, and necessitated temporary jugular or sub-clavian catheters for emergent dialysis, as a consequence, carrying a high risk of complications, such as hematoma, infection, and thrombosis. Access-related problems had been reported to account for 48% of all hospitalization [41]. Presence of diabetes can be a significantly poor predictor for primary and secondary success of vascular access [42]. Consistent with this notion is that our data showing a higher
Fig. 3. The impact of diabetes on frequency of hospitalization and hospital days per patient-year in diabetic vs. non-diabetic dialysis patient.
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Fig. 4. The causes of hospitalization in diabetic vs. non-diabetic dialysis patients. CAD: coronary artery disease; CHF: congestive heart failure; PVD: peripheral vascular diseases; Vascular access: failure of vascular access; and ANS dysfunction: autonomous nervous system dysfunction.
rate of failure of vascular access and access-related infections leading to a higher inpatient costs in diabetic patients (Fig. 4). In summary, diabetes has become the most common cause of new patients requiring renal replacement therapy, and consequently, incurring a tremendous burden on economic costs due to the growing number of diabetic population and its associated high co-morbidity. Once overt diabetic nephropathy develops, vigorous management should be given to provide a cost-effective care, including tight blood pressure control, intensive glycemic control, use of ACE inhibitors/A-II receptor antagonists, administration of lipid-lowering agents, timely placement of vascular access, and correction of renal anemia. When patients reach stage of ESRD, kidney transplantation should be considered in terms of patient survival and cost savings [43,44]. An interdisciplinary care is essential to accomplish such a purpose in the whole clinical spectrum of diabetic nephropathy. Acknowledgements The study was supported by the research grants from Bristol-Meyer Squibb Co. Taiwan and Ching-Mei Paper Co. Ltd. We also thank Ms Hui-Mei Lin and Ms Keri Yang for their helpful preparations of this manuscript.
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