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High Risk and High CostFocus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Production of this document is made possible by financial contributions from Health Canada and provincial and territorial governments. The views expressed herein do not necessarily represent the views of Health Canada or any provincial or territorial government.
Unless otherwise indicated, this product uses data provided by Canada’s provinces and territories.
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The contents of this publication may be reproduced unaltered, in whole or in part and by any means, solely for non-commercial purposes, provided that the Canadian Institute for Health Information is properly and fully acknowledged as the copyright owner. Any reproduction or use of this publication or its contents for any commercial purpose requires the prior written authorization of the Canadian Institute for Health Information. Reproduction or use that suggests endorsement by, or affiliation with, the Canadian Institute for Health Information is prohibited.
For permission or information, please contact CIHI:
Canadian Institute for Health Information495 Richmond Road, Suite 600Ottawa, Ontario K2A 4H6
Phone: 613-241-7860Fax: [email protected]
ISBN 978-1-77109-555-6 (PDF)
© 2016 Canadian Institute for Health Information
How to cite this document:Canadian Institute for Health Information. High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada. Ottawa, ON: CIHI; 2016.
Cette publication est aussi disponible en français sous le titre Coûts et risques élevés : regard sur les possibilités de réduire les hospitalisations chez les patients en dialyse au Canada.ISBN 978-1-77109-556-3 (PDF)
Table of contentsAcknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Key findings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Study cohort and methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Appendix: Data tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
AcknowledgementsThe Canadian Institute for Health Information (CIHI) would like to thank the Expert Advisory Group for its invaluable advice on the report High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada:
• S. Joseph Kim, Co-Director, Kidney Transplant Program, Toronto General Hospital
• Scott Klarenbach, Professor of Medicine, University of Alberta
• Jean-Philippe Lafrance, Nephrologist, Maisonneuve-Rosemont Hospital
• Louise Moist, Professor of Medicine and Epidemiology, University of Western Ontario
• Manish M. Sood, Assistant Professor of Medicine, The Ottawa Hospital
• Naisu Zhu, Senior Methodologist, Methodologies and Specialized Care, CIHI
The following individuals participated in a peer review of this report:
• Susan M. Samuel, Pediatric Nephrologist, Alberta Children’s Hospital
• Joanne Kappel, Nephrologist, University of Saskatchewan
Please note that the analyses and conclusions in the present document do not necessarily reflect those of the Expert Advisory Group (organizations/individuals) or the peer reviewers mentioned above.
CIHI also wishes to acknowledge and thank the following individuals for their contribution:
• Frank Ivis, Senior Analyst, CORR, CIHI
• Kelvin Lam, Senior Analyst, CORR, CIHI
• Noura Redding, Coordinator, CORR, CIHI
• Michael Terner, Program Lead, CORR, CIHI
• Greg Webster, Director, Acute and Ambulatory Care Information Services, CIHI
• Juliana Wu, Manager, CORR, CIHI
5
High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Key findingsIn 2014, there were 20,690 patients on dialysis in Canada, a number that had increased more than 30% in the previous 10 years. Yearly health expenditures for these patients total approximately $1.9 billion, or 1.1% of total health expenditures in Canada (excluding Quebec). Patients on dialysis have high health care needs that go beyond their regular dialysis treatments, including inpatient hospitalizations. This report highlights factors related to the risk of hospitalization for dialysis patients, which is an important step in reducing the number of hospitalizations in Canada.
In Canada, dialysis patients are hospitalized an average of 1.1 times per patient per year. In 2014, this was approximately 23,000 hospitalizations for all dialysis patients in Canada (excluding Quebec). With an average estimated cost of $13,634 per hospitalization of a dialysis patient, the total inpatient cost for this group is approximately $310 million per year. Key findings from this study include the following:
• Theriskofbeinghospitalizedforanyreasonishighestinthefirstweekofdialysis;theriskforperitonealdialysispatientsis27%higherthantheriskforhemodialysispatientsinthefirstweek.Forhospitalizationsfordialysis-relatedinfections,theriskremainshigherforperitonealdialysispatients,whereastheriskforhemodialysispatientsdecreasesovertime.
– Ways to reduce catheter and surgically created vascular access infections include increasing arteriovenous fistula use for vascular access, following published dialysis-specific guidelines for preventing infection, and supporting and educating patients who are initiating peritoneal dialysis treatments.
• Amongdialysispatients,pediatricpatients(age17andyounger)areat1.73timeshigherriskofbeinghospitalizedthanpatientsage45to64,evenwhencontrollingforrace,sexandotherfactors.Theaveragecostsofpediatrichospitalizationsarealsohigherthanthoseforolderpatientsondialysis.
– Reducing time on dialysis through earlier transplantation would reduce the number of dialysis-related hospitalizations for these patients.
• Indigenouspatientsondialysisareatahigherriskofbeinghospitalized(30%higherriskfordialysis-relatedinfectionand20%higherriskforallcauses)thannon-Indigenouspatientsondialysis.ThishigherriskexistsforIndigenouspatientsevenwhencontrollingforage,otherdiseasesandneighbourhoodincome.
– Adopting and expanding programs designed to improve care for Indigenous patients can improve outcomes and reduce avoidable hospitalizations. These programs include using mobile clinics, establishing satellite dialysis facilities in Indigenous communities and conducting cultural education of health care professionals.
6
High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
IntroductionIn Canada, the number of patients with end-stage kidney disease (ESKD) who receive dialysis treatments has increased steadily, rising 31% from 15,827 patients in 2005 to 20,690 patients in 2014.1 Patients on dialysis require a significant amount of health care resources. The total annual cost to care for a patient on dialysis ranges from $56,000 to $107,000, depending on the type of dialysis treatment.2 Using published dialysis cost estimates as well as expenditure and dialysis statistics from 2014,1, 3 expenditures for dialysis patients total approximately $1.9 billion a year, or 1.1% of total health expenditures in Canada (excluding Quebec).
Beyond the dialysis treatment itself, the second-largest cost for these patients is often for hospital admissions.2 Dialysis patients are at a higher risk of multiple admissions to hospital than either non–kidney disease patients or patients with chronic kidney disease.4 In the Canadian case-mix grouping methodology used for inpatient hospital care, dialysis is 1 of the 16 flagged intervention factors used for complex patients requiring higher hospital resource use.5 Therefore, dialysis-dependent patients are considered a high-cost group for inpatient hospital care. As the number of dialysis patients continues to rise in Canada, so will their inpatient hospital care costs.
In the United States, hospitalization rates for dialysis patients are monitored and regularly reported. The United States Renal Data System (USRDS) reported that over the last decade, hospitalization rates for any reason (all causes) among dialysis patients went down from 2.1 visits per patient for every year on dialysis to 1.7 visits.6 Reporting on hospitalizations in the United States focuses on cardiovascular-, infection- and vascular access–related hospitalizations that are considered preventable. Reducing avoidable hospitalizations among dialysis patients has the potential to lead to better patient outcomes and significant savings for health care systems. In September 2016, the American Society of Nephrology (ASN) announced a partnership with the United States government to implement the Nephrologists Transforming Dialysis Safety Project, with the goal of protecting dialysis patients from potentially fatal infections.7 The ASN stated that in the United States, infections in dialysis patients are the second leading cause of death. The focus in the United States on reducing hospitalizations and preventing infections related to dialysis could be a model for similar efforts in Canada.
To date, published research in Canada examining the rates of all-cause and infection-related hospitalizations among dialysis patients has been limited to studies done in a single centre or a single province.8, 9 This report uses pan-Canadian data to highlight the factors affecting hospitalization rates among dialysis-dependent ESKD patients and the associated costs of these hospitalizations.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
End-stage kidney disease in Canada and the Canadian Organ Replacement RegisterESKD is the final stage of chronic kidney disease, where kidney function is reduced to a level so low that the kidneys can no longer sufficiently filter blood, control fluid levels in the body or produce hormones to maintain health. There are many causes of ESKD, including high blood pressure and vascular disease, glomerulonephritis (a group of inflammatory disorders), kidney damage from drugs, inherited disorders and — the most common cause — diabetes.
Once a patient’s kidneys fail, he or she has 4 treatment options. The first 3 are renal replacement therapies: hemodialysis (HD), peritoneal dialysis (PD) and kidney transplantation. The fourth treatment option is non-dialysis supportive care designed to maintain remaining kidney function for as long as possible. A transplanted kidney can restore kidney function until such time as the transplanted kidney fails. Dialysis entails cleaning the blood through artificial means, and includes HD (81% of dialysis patients in Canada) and PD (19%).1
Both dialysis modalities require the use of dialyzing fluid to remove wastes from the blood. HD involves circulating blood from the body into a machine (a dialyzer) where the blood is exposed to dialyzing fluid and wastes are removed. PD involves inserting dialyzing fluid into the peritoneum (abdomen) where waste products from the blood dissolve into the fluid; this fluid is then changed 4 to 6 times a day to remove wastes. Both forms, or modalities, of dialysis involve a connection between the patient’s blood and a dialysis solution. This connection is made through either a catheter or a surgically created vascular access. All types of catheters and surgically created vascular access can become infected and may require in- or outpatient medical care. Both dialysis modalities can be done by the patient at home, but the majority of HD is done in dialysis treatment centres or hospitals (79% of dialysis patients in Canada).1 Patients can switch between modalities and may move between a kidney transplant (when a kidney donor is available) and dialysis (when a transplanted kidney fails). Dialysis tends to have poor patient outcomes, with only 43% of patients surviving longer than 5 years.1 Survival on dialysis also varies widely by age group.
The Canadian Organ Replacement Register (CORR) is a pan-Canadian information system that follows patients from their first treatment for end-stage kidney failure until their death. CORR collects data for patients on renal replacement therapy, including data on dialysis treatments, transplantation and patient outcomes. In 2014, as reported by CIHI, a total of 5,116 newly diagnosed kidney failure patients started dialysis in Canada (excluding Quebec), and 20,690 patients were receiving dialysis treatments, a rate of 757 patients per million population.1
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Study cohort and methodologyData sourcesThis study used data from 4 CIHI data sources. CORR was used to identify dialysis-dependent ESKD patients, as well as their demographic and dialysis-related information. These patient records were linked to hospitalization records from the Discharge Abstract Database (DAD) and the Ontario Mental Health Reporting System (OMHRS) to determine the rate of hospitalization for the study cohort. These hospitalizations were then used in combination with CIHI’s Cost of a Standard Hospital Stay (CSHS) indicator, using data from the Canadian MIS Database, to calculate the estimated costs of hospitalizations.
Study cohortCORR captures patient-level data for dialysis-dependent patients with ESKD, defined as patients with a diagnosis of ESKD who have been on dialysis for at least 90 days. Quebec and Manitoba data is currently not linkable between CORR and the DAD, so these provinces are not part of the study cohort. The study cohort included incident (i.e., new) dialysis patients starting dialysis for the first time between January 1, 2005, and March 31, 2014. Hospitalization data for patients in the study cohort included 6 months before beginning dialysis (to calculate pre-dialysis stays in hospital) and a minimum of 1 year after the patient initiated dialysis. As well as patients in Quebec and Manitoba, patients with non-linkable health care numbers and patients who had a kidney transplant before initiating dialysis were excluded. The final study cohort included 38,369 patients.
Inpatient hospital costs Hospitalization costs were estimated using CIHI’s CSHS indicator and record-level Resource Intensity Weights for each hospitalization.10 Comparable costing data from fiscal years 2010–2011 to 2013–2014 was used for this analysis. The cost analysis excluded atypical hospitalizations, such as deaths, sign-outs, transfers and long-stay outliers. Hospitalization costs were estimated at the province level and combined to a pan-Canadian (excluding Quebec and Manitoba) estimate.
9
High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Unadjusted rates and reason for hospitalizationCrude rates for admission over time and in-hospital mortality rates over time are presented in the unit of the patient year. A patient year is equivalent to 1 dialysis patient being on dialysis for a single year. This unit was used to compare across groups with different numbers of patients on dialysis for various lengths of time. Cause of hospitalization was determined using the most responsible diagnosis recorded in the DAD, which is the single diagnosis or condition described as being most responsible for the patient’s stay in hospital. If there were multiple diagnoses or conditions, the one that was most responsible for the greatest use of resources is recorded as the most responsible diagnosis in the DAD.
Statistical analysesA stratified, gamma-distributed frailty model was the statistical model used in this study to assess repeated admissions and determine the inter-recurrence dependence of hospitalization within individuals, as well as the hazard ratio (HR) attributed to each covariate. This frailty model was chosen to accommodate repeat hospitalizations from patients during the follow-up period. The frailty model was stratified by 4 regions: Atlantic Canada; Ontario; Saskatchewan, Alberta, the Northwest Territories and Nunavut; and British Columbia and Yukon. Patients were censored at the date they died, received a kidney transplant, withdrew from dialysis or were lost to follow-up.
The 2 outcomes in the statistical model were risk of hospitalization for any cause (all-cause hospitalization) and risk of an infection-related hospitalization (IRH). The IRH was specific to dialysis-related infections, such as those related to a vascular access device, septicemia (infections in the blood) and peritonitis (infections in the lining of the body cavity where dialysis fluid is used for patients on PD). The covariates included time-dependent dialysis modality (HD versus PD), dialysis care type (in centre versus home), age, sex, race and ethnicity (self-identified), comorbidity, neighbourhood income, total length of stay in hospital in the 6 months before starting dialysis, primary diagnosis for ESKD and year of dialysis start. Patients can switch dialysis modalities over time; therefore, the modality covariate was included as a time-dependent variable within the model.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
ResultsThe study cohort profile is presented in the appendix.
During the study period, there were 112,374 hospitalizations for the study cohort; 12,931 (11.5%) of these hospitalizations were for infections related to dialysis treatments. Crude hospitalization rates for both all-cause hospitalizations and IRHs are presented in Figure 1. For all-cause hospitalizations, the rates across age groups ranged from 1.1 to 2.5 hospitalizations per patient year. Rates of hospitalization were similar for the 3 older age groups; pediatric patients had rates of hospitalization that remained 20% to 130% higher than for the other age groups. For the rate of IRHs, pediatric patients who were on dialysis had consistently higher rates than the other age groups after patients were on dialysis for more than 7 days. The IRH rates across age groups ranged from 0 to 0.21 hospitalizations per patient year. The IRH rate increased over time for pediatric patients, whereas older age groups had steady rates once they were on dialysis for more than 7 days. For patients who died in hospital, rates were in the range of 0 to 0.14 deaths per patient year.
Among pediatric patients, kidney disease was listed as the most responsible diagnosis for 290 (25.7%) hospitalizations, and infections related to dialysis were the primary reason for 132 (11.7%) hospitalizations. Among patients age 18 to 64, kidney disease was the primary reason for 3,399 (6.2%) hospitalizations, and infections related to dialysis were the primary reason for 5,413 (9.9%) hospitalizations. Other primary reasons for hospitalization for those 18 to 64 included diabetes (7,908; 14.5% of hospitalizations) and cardiovascular disease (angina and heart attacks: 1,809; 3.3%). Among individuals age 65 and older, infections related to dialysis (5,140; 9.1% of hospitalizations), diabetes (4,311; 7.6%), cardiovascular disease (2,975; 5.3%) and kidney disease (1,823; 3.2%) were the most common reasons for hospitalization.
11
High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Figure 1 Crude hospitalization and in-hospital mortality rates over time by age group
0.00
0.05
0.10
0.15
0.20
0.25
Days after dialysis start
0.000.020.040.060.080.100.120.14
0 50 100 150 200 250 300 350 400
c) All-cause in-hospital mortality rate
In-ho
spita
l mor
tality
rate
per p
atien
t yea
r
Age 18–44 Age 0–17 Age 45–64 Age 65+
0 50 100 150 200 250 300 350 400Days after dialysis start
b) Infection-related hospitalization rate
Age 18–44 Age 0–17 Age 45–64 Age 65+
0.0
0.5
1.0
1.5
2.5
3.0
2.0
0 50 100 150 200 250 300 350 400
Rate
of ad
miss
ionpe
r pati
ent y
ear
Rate
of ad
miss
ionpe
r pati
ent y
ear
Days after dialysis start
a) All-cause hospitalization rate
Age 18–44 Age 0–17 Age 45–64 Age 65+
NotesPatients age 65 to 74 and age 75 and older were combined into a single 65+ age group for this analysis.Data tables for Figure 1 are available in the appendix. Sources Canadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
The hazard ratios for all-cause hospitalizations and IRHs that were calculated from the statistical model are presented in Table 1 (the modality covariate is presented in Figure 2). Compared with dialysis patients age 45 to 64, pediatric patients (HR = 2.73; p-value <0.001) and 18- to 44-year-old patients (HR = 1.21; p-value <0.001) had higher risks of being hospitalized; these risks were statistically significant. When limited to IRHs, the trends were similar, though not statistically significant. Female dialysis patients had a statistically significantly higher risk (HR = 1.08; p-value <0.001) of hospitalization than males for all-cause admissions and a higher risk (HR = 1.03; p-value = 0.422) for IRHs.
Examining race and ethnicity of dialysis patients, Asian (HR = 0.72; p-value <0.001), Indian subcontinent (HR = 0.78; p-value <0.001) and black (HR = 0.86; p-value <0.001) patients had a lower risk of hospitalization than Caucasian patients, whereas Indigenous patients (HR = 1.20; p-value <0.001) were at a higher risk. Results were similar for the risk of IRHs. Neighbourhood income quintile was also examined, but there was no significant trend across income groups.
Patients who had dialysis treatments at home were at a lower risk of both all-cause hospitalization (HR = 0.84; p-value <0.001) and IRH (HR = 0.85; p-value = 0.013) compared with patients who received treatment in a dialysis facility. Dialysis patients who were hospitalized in the 6 months before they started dialysis had a 2% higher risk (p-value <0.001) of all-cause hospitalization and a 5% higher risk (p-value <0.001) of IRH for every week they stayed in hospital before beginning dialysis.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Table 1 Risk of hospitalization for dialysis-dependent patients
Cofactor
All-cause hospitalizations Infection-related hospitalizationsHazard
ratio p-value 95% CIHazard
ratio p-value 95% CIAge group
0–17 2.73 <0.001 2.37–3.15 1.30 0.164 0.90–1.88
18–44 1.21 <0.001 1.15–1.27 1.03 0.703 0.90–1.16
45–64 1.00 — — 1.00 — —
65–74 0.95 0.006 0.91–0.98 0.96 0.432 0.88–1.06
75+ 1.01 0.739 0.97–1.05 1.02 0.724 0.92–1.12
SexFemale 1.08 <0.001 1.05–1.11 1.03 0.422 0.96–1.11
Male 1.00 — — 1.00 — —
RaceAsian 0.72 <0.001 0.68–0.77 0.76 <0.001 0.65–0.89
Indian subcontinent 0.78 <0.001 0.73–0.84 0.86 0.086 0.73–1.02
Indigenous 1.20 <0.001 1.12–1.28 1.30 0.001 1.11–1.53
Black 0.86 <0.001 0.80–0.93 0.98 0.800 0.81–1.18
Caucasian 1.00 — — 1.00 — —
Income quintile*5 (high) 1.02 0.519 0.97–1.06 1.07 0.274 0.95–1.20
4 0.96 0.082 0.92–1.01 0.98 0.675 0.87–1.09
3 0.97 0.133 0.93–1.01 1.00 0.960 0.90–1.12
2 0.98 0.230 0.94–1.02 1.05 0.342 0.95–1.17
1 (low) 1.00 — — 1.00 — —
Care location Home 0.84 <0.001 0.79–0.88 0.85 0.013 0.75–0.97
In centre 1.00 — — 1.00 — —
DiagnosisGlomerulonephritis 1.00 — — 1.00 — —
Diabetes 1.17 <0.001 1.11–1.22 1.17 0.014 1.03–1.33
Renal vascular disease 1.00 0.959 0.95–1.06 0.95 0.444 0.82–1.09
Congenital/hereditary 0.92 0.021 0.85–0.99 0.78 0.014 0.64–0.95
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Cofactor
All-cause hospitalizations Infection-related hospitalizationsHazard
ratio p-value 95% CIHazard
ratio p-value 95% CIComorbidity
Cardiovascular disease 1.14 <0.001 1.10–1.18 1.05 0.267 0.96–1.14
Congestive heart failure 1.13 <0.001 1.09–1.17 1.04 0.361 0.95–1.14
Cerebrovascular disease 1.06 0.009 1.01–1.10 1.07 0.253 0.96–1.19
Peripheral vascular disease 1.16 <0.001 1.12–1.21 1.17 0.003 1.06–1.29
Diabetes† 1.10 <0.001 1.05–1.15 1.27 <0.001 1.13–1.42
Malignancy 1.21 <0.001 1.16–1.26 1.19 0.002 1.07–1.33
COPD 1.15 <0.001 1.10–1.21 1.21 <0.001 1.08–1.36
Hypertension 0.90 <0.001 0.87–0.94 0.84 <0.001 0.76–0.93
Pre-dialysis hospitalizationEvery week in hospital before dialysis start
1.02 <0.001 1.02–1.03 1.05 <0.001 1.04–1.06
Notes* Patient-level household income is an estimate using neighbourhood income levels. Neighbourhood income is divided
into 5 groups, referred to as quintiles, based on Statistics Canada data.† The diabetes comorbidity covariate excludes patients with a primary ESKD diagnosis of diabetes.— Not applicable.CI: Confidence interval; COPD: Chronic obstructive pulmonary disease.SourcesCanadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
Patients can switch modalities of dialysis treatment over time; therefore, hazard ratios for these variables (HD and PD) were estimated at different time periods after patients started dialysis. The results of these analyses are presented in Figure 2 for all-cause hospitalizations and IRHs. For all-cause hospitalizations, patients on either HD or PD had similarly decreasing risks of hospitalization over time after beginning dialysis. The exception was within the first 7 days after starting PD, where these patients were at a higher risk of hospitalization than patients on HD; this risk was statistically significant. For IRHs, patients on PD had higher risks of hospitalization than patients on HD, though the risk was statistically significant only within the first 7 days after starting dialysis.
15
High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Figure 2 Comparative risk of hospitalization over time by modality type
≤7 days 8–30 days 1–3 months 3–6 months 6–12 months
Haza
rd rat
ioHa
zard
ratio
a) All-cause hospitalizations
b) Infection-related hospitalizations
0.00.20.40.60.81.01.21.41.61.82.0
Time after dialysis startHemodialysis Peritoneal dialysis
Time after dialysis startHemodialysis Peritoneal dialysis
≤7 days 8–30 days 1–3 months 3–6 months 6–12 months0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
NotesThe line on the x-axis at 1.0 is the reference value for HD, ≤7 days after dialysis start.A data table for Figure 2 is available in the appendix. Sources Canadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
The hospital-associated costs for dialysis patients are presented in Table 2. The average cost per patient year increased with decreasing age, from $8,149 for patients age 75 and older to $27,344 for pediatric patients. When the pediatric age group was divided into smaller
16
High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
groups (0 to 4, 5 to 9, 10 to 14 and 15 to 17), the observed trend of increased hospital costs with decreasing age continued; those age 0 to 4 had an average inpatient hospitalization cost of $53,441 (data presented in the supplementary data tables in the companion products) per year on dialysis. There was little difference in hospital costs between HD and PD patients as well as between patients on dialysis at home and in centre. For the 4 years of available cost data, the average cost per patient increased each fiscal year, from $9,248 in 2010–2011 to $10,732 in 2013–2014.
Table 2 Hospital costs for inpatient hospitalizations of dialysis-dependent patients
a) Hospital cost by age group, modality and care location
VariableAverage in-hospital LOS
(days)Median in-hospital LOS
(days)Average cost per
patient year on dialysisAge group
0–17 8.0 4 $27,344
18–44 6.6 4 $11,351
45–64 7.4 5 $10,982
65–74 7.8 5 $9,180
75+ 7.8 5 $8,149
ModalityHD 7.5 5 $9,942
PD 7.5 5 $9,858
Care locationIn centre 7.4 5 $10,001
Home 7.6 5 $9,647
b) Hospital cost by fiscal year
VariableAverage cost per
patient year on dialysisYear-over-year change
(%)Fiscal year
2010–2011 $9,248 n/a
2011–2012 $9,373 1.4
2012–2013 $10,177 8.6
2013–2014 $10,732 5.5
NotesLOS: Length of stay; HD: Hemodialysis; PD: Peritoneal dialysis; n/a: Not applicable.Analysis includes hospitalizations between 2010–2011 and 2013–2014.Excludes atypical hospitalizations (e.g., deaths, sign-outs, transfers, long-stay outliers).Modality variable is determined at start of dialysis. SourcesCanadian Organ Replacement Register, Discharge Abstract Database, Ontario Mental Health Reporting System and Canadian MIS Database, 2016, Canadian Institute for Health Information.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
DiscussionIn this analysis of 38,369 incident dialysis patients in Canada, we found that a large number of patients required hospitalization, with many hospitalizations attributable to dialysis itself. The risk of hospitalization differed by demographic and clinical risk factors. Within the first year after starting dialysis, the average rate of hospitalization for dialysis-dependent ESKD patients in Canada ranged from 1.1 to 1.4 hospitalizations per patient year, 11.5% of which were an IRH (data not shown). This is consistent with, yet lower than, rates reported in the United States, where the USRDS has reported an adjusted rate of 1.7 hospitalizations per patient year for dialysis patients.6
Reporting on hospitalizations for dialysis patients serves to inform strategies that can reduce preventable admissions and rehospitalizations. For example, the USRDS has reported that interventions have been developed to reduce infection rates that can lead to an IRH for a PD patient. The USRDS has also reported that rates of all-cause hospitalization for ESKD patients fell by 19% between 2005 and 2013, demonstrating the value of understanding hospitalization data for ESKD patients.6
Several groups of dialysis patients have higher risks of hospitalization. Crude hospitalization rates were consistently higher among pediatric patients than among all other age groups. Compared with 45- to 64-year-old patients, pediatric patients had a 173% higher risk of being hospitalized and a 30% higher risk of having an IRH. The costs of hospitalization for pediatric patients were also higher than for other age groups, with a trend of increasing cost with decreasing age. The main reasons that pediatric dialysis patients were hospitalized tended to be related to kidney disease and infections related to dialysis.
These findings demonstrate the relatively higher health care needs of pediatric patients on dialysis compared with older patients. Pediatric patients may also encounter challenges with access to care, as they are usually treated in children’s hospitals, which are fewer and located in large urban centres in Canada. These patients have good survivability with relatively low in-hospital mortality, as well as good patient outcomes resulting from being on dialysis for a shorter time before receiving a kidney transplant compared with adult dialysis patients. In 2014, the median time that a pediatric patient was on dialysis before a kidney transplant from a deceased donor was 1.5 years (excluding pre-emptive transplants), which was significantly shorter than the time for adult patients, who had a median time on dialysis of 4.1 years.1 Reducing time on dialysis through earlier transplantation would reduce the number of dialysis-related hospitalizations for these patients.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Indigenous dialysis patients also have higher hospitalization rates relative to their peers. Even when controlling for variables such as diabetes, age and income, Indigenous dialysis patients had a 20% higher risk of being admitted to hospital and a 30% higher risk of having an IRH than Caucasian patients. A 2013 CIHI study on kidney transplantation in Indigenous populations showed that Indigenous patients were more likely to need renal replacement therapy and to travel longer distances to receive dialysis treatment, were less likely to receive a kidney transplant and had lower patient survival rates than non-Indigenous patients.11 These are all factors that likely lead to higher hospitalization rates for these patients.
CIHI’s 2013 report on ESKD in Indigenous people in Canada included a discussion of potential solutions to ease the high burden of ESKD care in this population. Some interventions that have been tested or instituted include using mobile clinics to screen for kidney disease complications, establishing satellite dialysis facilities in Indigenous communities, conducting cultural education of health care professionals, establishing specialty self-management counselling and weekly screening clinics, and developing a culture-specific dialysis toolkit.11
Several studies have investigated hospitalizations among HD and PD patients. Using data from Quebec, a 2015 study reported no statistically significant differences in all-cause readmission between the 2 modalities, but a statistically higher risk of a subsequent IRH for PD patients.12 A study published in 2002 that used data from the Calgary region reported that in-centre HD patients had higher inpatient costs than PD patients, who in turn had higher costs than patients receiving HD care from a satellite facility or on home HD.13 The USRDS reported that HD patients have higher adjusted hospitalization rates but fewer adjusted hospital days than PD patients.6
Our study attempts to provide a picture of the risk of hospitalization over time for HD and PD patients in Canada. It found that for PD patients, the risk of hospitalization, both all cause and infection related, was significantly higher than for HD patients within the first 7 days of dialysis initiation, but that the risk of all-cause hospitalization decreased after 7 days to a level similar to that for HD patients; however, the risk of IRH remained higher for PD patients than for HD patients over time. The higher rate of IRH for PD patients is consistent with a published study conducted with dialysis patients from Quebec.14 Among HD patients, the risk of all-cause hospitalization decreased significantly over time after dialysis initiation.
Interventions to reduce infections among dialysis patients have been extensively studied. A 2015 study on IRHs and dialysis modality highlighted the importance of education and training for patients in preventing infections from the peritoneal catheter and resulting peritonitis.12 More specifically, support for patients initiating PD can help reduce hospitalizations during the period of highest risk for these patients.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
The method of vascular access can be an important consideration for risk of infection. The greater risk of catheters over arteriovenous fistula is well known.15 In 2014, researchers from the United Kingdom discussed increasing arteriovenous fistula use for vascular access when starting dialysis to reduce infections from central venous access catheters.16 This study also discussed following published dialysis-specific guidelines for the prevention of infection.17, 18 In a 2013 study of vascular access use internationally, Canada had the highest use of catheters (45%) and the lowest use of arteriovenous fistula (49%) among 14 countries.19 In Canada, there are opportunities to increase arteriovenous fistula use, which could decrease hospitalizations for treating dialysis-related infections.
Dialysis is an expensive therapy for ESKD patients, but a large proportion of the costs of care for an ESKD patient are attributed to inpatient hospital care. Dialysis patients have a higher hospitalization rate than the general population, and the average estimated cost of a hospital stay is also higher ($13,634 and $6,066, respectively; data not shown). i In Canada, we found that dialysis patients are hospitalized 1.1 times per patient year. In 2014, this was approximately 23,000 hospitalizations for all dialysis patients in Canada (excluding Quebec). The estimated total inpatient cost for this group is approximately $310 million per year. Reducing the number of hospitalizations for these patients would lead to significant savings for Canadian health care systems.
This study included the largest cohort of its kind in Canada but has several limitations that should be stated:
• It did not include patients treated in Quebec or Manitoba facilities.
• Comorbidities and most risk factors were captured at the time when a patient started dialysis and registered with CORR; these risk factors may have changed over the course of the study.
• There is a possibility of data quality issues related to the reporting of dialysis start date for PD patients. Because of differences in how patients are educated for PD initiation during the first 2 weeks of therapy, the practice of capturing start date may differ slightly among facilities.
Dialysis-dependent patients in Canada experience a considerable number of hospitalizations, which significantly affects patients and health care systems. Further areas of research include rates of readmission, the association between vascular access type and hospitalization, emergency department use by dialysis patients and a comparison of hospitalization rates between dialysis and kidney transplant recipient patients. Targeted national interventions such as adherence to guidelines on avoiding catheter infections and promoting greater arteriovenous fistula use could reduce the hospitalization rate for dialysis patients in Canada.
i. The average estimated cost of a hospital stay for the general population excludes Quebec and Manitoba to match the study cohort. The average estimated cost of a hospital stay for dialysis patients was calculated using the national average (excluding Quebec and Manitoba) multiplied by the average Resource Intensity Weights for dialysis patients.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Appendix: Data tables
Table A1 Cohort profile
Variable Number of patients Percentage of patientsAge group
0–17 281 0.7%
18–44 4,097 10.7%
45–64 12,798 33.4%
65–74 9,811 25.6%
75+ 11,382 29.7%
SexFemale 14,979 39.0%
Male 23,390 61.0%
RaceCaucasian 26,988 70.3%
Asian 2,554 6.7%
Indian subcontinent 2,044 5.3%
Indigenous 1,777 4.6%
Black 1,430 3.7%
Other or unknown 3,576 9.3%
Income quintile*5 (high) 5,588 14.6%
4 6,764 17.6%
3 7,325 19.1%
2 8,386 21.9%
1 (low) 9,587 25.0%
Missing data 719 1.9%
Province/territory†
British Columbia 6,696 17.5%
Alberta 4,483 11.7%
Saskatchewan 1,729 4.5%
Ontario 21,743 56.7%
New Brunswick 1,032 2.7%
Nova Scotia 1,437 3.7%
Prince Edward Island 193 0.5%
Newfoundland and Labrador 1,008 2.6%
Territories 48 0.1%
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Variable Number of patients Percentage of patientsModality
HD 30,777 80.2%
PD 7,592 19.8%
Care locationIn centre 30,860 80.4%
Home 7,509 19.6%
Primary diagnosisDiabetes 13,863 36.1%
Renal vascular disease 7,104 18.5%
Glomerulonephritis 4,924 12.8%
Etiology uncertain 3,035 7.9%
Congenital/hereditary 2,190 5.7%
Other 4,963 12.9%
Missing data 2,290 6.0%
ComorbidityCardiovascular disease 11,339 29.6%
Congestive heart failure 8,757 22.8%
Cerebrovascular disease 4,982 13.0%
Peripheral vascular disease 6,065 15.8%
Diabetes‡ 4,982 13.0%
Malignancy 5,061 13.2%
COPD 4,281 11.2%
Hypertension 29,336 76.5%
Pre-dialysis hospitalizations§
0 12,910 33.6%
1 16,070 41.9%
2 5,931 15.5%
3 2,150 5.6%
4 817 2.1%
5 313 0.8%
6 98 0.3%
7+ 80 0.2%
Notes* Patient-level household income is an estimate using neighbourhood income levels. Neighbourhood income is divided
into 5 groups, referred to as quintiles, based on Statistics Canada data.† Province/territory is determined by issuance of health card.‡ The diabetes comorbidity variable excludes patients with a primary ESKD diagnosis of diabetes.§ Denotes the number of hospital admissions within 6 months before first dialysis treatment.HD: Hemodialysis; PD: Peritoneal dialysis; COPD: Chronic obstructive pulmonary disease.All variables are captured at the start of dialysis.SourcesCanadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Table A2 Data for Figure 1a: Crude all-cause hospitalization rate over time by age group
Age group 7 days 30 days 3 months 6 months 1 year0–17 1.67 2.48 2.49 2.42 2.47
18–44 1.38 1.31 1.22 1.18 1.14
45–64 1.27 1.32 1.18 1.12 1.06
65+ 1.40 1.35 1.26 1.18 1.10
NotesPatients age 65 to 74 and age 75 and older were combined into a single 65+ age group for this analysis.All time points are relative to the start date of dialysis.The rate unit is the rate of admission per patient year.SourcesCanadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
Table A3 Data for Figure 1b: Crude infection-related hospitalization rate over time by age group
Age group 7 days 30 days 3 months 6 months 1 year0–17 0.00 0.13 0.16 0.18 0.21
18–44 0.08 0.12 0.12 0.11 0.12
45–64 0.09 0.13 0.12 0.12 0.12
65+ 0.12 0.13 0.13 0.13 0.12
NotesPatients age 65 to 74 and age 75 and older were combined into a single 65+ age group for this analysis.All time points are relative to the start date of dialysis.The rate unit is the rate of admission per patient year.SourcesCanadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
Table A4 Data for Figure 1c: Crude all-cause in-hospital mortality rate over time by age group
Age group 7 days 30 days 3 months 6 months 1 year0–17 0.000 0.000 0.015 0.008 0.013
18–44 0.013 0.018 0.019 0.025 0.022
45–64 0.033 0.047 0.057 0.058 0.060
65+ 0.089 0.127 0.139 0.131 0.129
NotesPatients age 65 to 74 and age 75 and older were combined into a single 65+ age group for this analysis.All time points are relative to the start date of dialysis.The rate unit is the in-hospital mortality rate per patient year.SourcesCanadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
Table A5 Data for Figure 2: Comparative risk of hospitalization over time by modality type
Modality effect by time on dialysis
All-cause hospitalizations Infection-related hospitalizationsHazard ratio 95% CI Hazard ratio 95% CI
HD7 days or less (reference group) 1.00 — 1.00 —
8–30 days 0.76 0.68–0.86 0.87 0.56–1.36
31–90 days 0.62 0.53–0.72 0.98 0.55–1.74
91 days–6 months 0.56 0.47–0.65 0.69 0.37–1.29
6 months–1 year 0.53 0.45–0.63 0.52 0.22–1.24
PD7 days or less 1.27 1.07–1.50 2.05 1.19–3.55
8–30 days 0.73 0.62–0.85 1.24 0.70–2.19
31–90 days 0.52 0.44–0.62 1.38 0.77–2.49
91 days–6 months 0.53 0.45–0.63 1.43 0.76–2.71
6 months–1 year 0.56 0.47–0.67 1.34 0.56–3.22
Notes— Not applicable.CI: Confidence interval; HD: Hemodialysis; PD: Peritoneal dialysis.SourcesCanadian Organ Replacement Register, Discharge Abstract Database and Ontario Mental Health Reporting System, 2016, Canadian Institute for Health Information.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
References 1. Canadian Institute for Health Information. Canadian Organ Replacement Register Annual
Report: Treatment of End-Stage Organ Failure in Canada, 2005 to 2014. 2016.
2. Klarenbach SW, Tonelli M, Chui B, Manns BJ. Economic evaluation of dialysis therapies. Nature Reviews Nephrology. November 2014.
3. Canadian Institute for Health Information. National Health Expenditure Trends, 1975 to 2015. 2015.
4. Daratha KB, Short RA, Corbett CF, Ring ME, Alicic R, Choka R, Tuttle KR. Risks of subsequent hospitalization and death in patients with kidney disease. Clinical Journal of the American Society of Nephrology. March 2012.
5. Canadian Institute for Health Information. Case Mix Decision-Support Guide: CMG+. 2009.
6. United States Renal Data System. Annual Data Report, 2015: Epidemiology of Kidney Disease in the United States. 2015.
7. American Society of Nephrology. Kidney Society partners with US government to prevent dialysis infections [media release]. Accessed September 7, 2016.
8. Lafrance JP, Rahme E, Iqbal S, Elftouh N, Laurin LP, Vallée M. Trends in infection-related hospital admissions and impact of length of time on dialysis among patients on long-term dialysis: A retrospective cohort study. CMAJ Open. May 2014.
9. Williams VR, Quinn R, Callery S, Kiss A, Oliver MJ. The impact of treatment modality on infection-related hospitalization rates in peritoneal dialysis and hemodialysis patients. Peritoneal Dialysis International. August 2011.
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11. Canadian Institute for Health Information. End-Stage Renal Disease Among Aboriginal Peoples in Canada: Treatment and Outcomes. 2013.
12. Laurin LP, Harrak H, Elftouh N, Ouimet D, Vallée M, Lafrance JP. Outcomes of infection-related hospitalization according to dialysis modality. Clinical Journal of the American Society of Nephrology. May 2015.
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High Risk and High Cost: Focus on Opportunities to Reduce Hospitalizations of Dialysis Patients in Canada
13. Lee H, Manns B, Taub K, Ghali WA, Dean S, Johnson D, Donaldson C. Cost analysis of ongoing care of patients with end-stage renal disease: The impact of dialysis modality and dialysis access. American Journal of Kidney Diseases. September 2002.
14. Lafrance JP, Rahme E, Iqbal S, Elftouh N, Vallée M, Laurin LP, Ouimet D. Association of dialysis modality with risk for infection-related hospitalization: A propensity score-matched cohort analysis. Clinical Journal of the American Society of Nephrology. October 2012.
15. Lata C, Girard L, Parkins M, James MT. Catheter-related bloodstream infection in end-stage kidney disease: A Canadian narrative review. Canadian Journal of Kidney Health and Disease. May 2016.
16. Collier S, Davenport A. Reducing the risk of infection in end-stage kidney failure patients treated by dialysis. Nephrology, Dialysis, Transplantation. December 2014.
17. O’Grady NP, Alexander M, Burns LA, Dellinger EP, Garland J, Heard SO, Lipsett PA, Masur H, Mermel LA, Pearson ML, Raad II, Randolph AG, Rupp ME, Saint S, Healthcare Infection Control Practices Advisory Committee. Guidelines for the prevention of intravascular catheter-related infections. American Journal of Infection Control. May 2011.
18. Piraino B, Bernardini J, Brown E, Figueiredo A, Johnson DW, Lye WC, Price V, Ramalakshmi S, Szeto CC. ISPD position statement on reducing the risks of peritoneal dialysis-related infections. Peritoneal Dialysis International. November 2011.
19. Pisoni RL, Zepel L, Port FK, Robinson BM. Trends in US vascular access use, patient preferences, and related practices: An update from the US DOPPS Practice Monitor with international comparisons. American Journal of Kidney Diseases. June 2015.
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