Concept: Risk of Chronic Kidney Disease (CKD) Progression to End Stage Kidney Disease (ESKD) - Heat Map
Last Updated: 2015-12-14
This concept describes the methods developed to measure the risk of chronic kidney disease (CKD) progression to end stage kidney disease (ESKD) as it was used in the
Care of Manitobans Living with Chronic Kidney Disease
Chartier et al. (2015).
This includes the age groups applied, the data sources used, the code values and conditions identifying the ranges employed in the measurements, and additional conditions / restrictions that are applied. A "heat map", originally developed by the
Kidney Disease Improving Global Outcomes (KDIGO) work group (2013)
and adapted for use in our research, is described and illustrates the risk of progression to ESKD. A link to the adapted "heat map" used in the deliverable is also provided.
Technical Definition of Risk of Progression
The technical definition for the risk of
chronic kidney disease (CKD)
end stage kidney disease (ESKD)
as described in Chartier et al. (2015) is as follows:
Children: 0-17 years old
- Adults: 18 years and older
- Children: 0-17 years old
- Diagnostic Services Manitoba (DSM) - now named Shared Health Diagnostic Services (SHDS) - Chemistry Data
Code Values and Conditions:
- The prognosis of CKD in Manitoba residents was evaluated based on the latest available laboratory results in the period April 1 2006 – March 31 2012. The following categories for
estimated glomerular filtration rate (eGFR)
were used to define increasing levels of kidney failure risk:
Persistent Albuminuria Categories
A1 (normal to mildly increased): ACR <3 mg/mmol or PCR <15 mg/mmol
A2 (moderately increased): ACR 3-30 mg/mmol or PCR 15-50 mg/mmol
A3 (severely increased): ACR >30 mg/mmol or PCR >50 mg/mmol
G1 (normal or high): eGFR values >=90
G2 (mildly decreased): eGFR values within 60-89
G3a (mildly to moderately decreased): eGFR values within 45-59
G3b (moderately to severely decreased): eGFR values within 30-44
G4 (severely decreased): eGFR values within 15-29
G5 (kidney failure): eGFR values <15
Note: The G1 and G2 categories in adults were combined to produce a category for normal eGFR of >= 60.
- A1 (normal to mildly increased): ACR <3 mg/mmol or PCR <15 mg/mmol
The Heat Map - Mapping Categories of Risk
To determine the likelihood of progression to ESKD, we adapted a "heat map" (a colour-coded classification table) developed in January 2013 by the Kidney Disease Improving Global Outcomes (KDIGO) Work Group (Kidney Disease Improving Global Outcomes (KDIGO), 2013). This new approach for prognosis of CKD was built on the recognition that albuminuria is an important marker of kidney function and risk of progression to ESKD, and it uses both albuminuria categories and eGFR to identify four levels of risk:
green: lowest risk (eGFR and albuminuria are normal or mildly abnormal)
yellow: moderately increased risk
orange: high risk
- red: the highest risk of all.
light purple: likely at lower risk
dark purple: likely at higher risk, and
- white: unknown risk.
Low Risk: Albuminuria A1 or A2, or eGFR G1, G2 or G3a.
- High Risk: Albuminuria A3 or eGFR G3b, G4 or G5.
We modified this table by adding three additional categories to represent people with CKD who have an incomplete set of laboratory tests (one of the two laboratory tests, providing some indications of risk level) or who do not have any laboratory tests (unknown risk level). These additional categories included:
In the event that only one of albuminuria or eGFR could be categorized, those who also met the administrative definition for CKD were assigned the following risk categories:
Those who met the administrative definition of CKD with no laboratory data to provide information about severity of risk were assigned to the Unknown Risk category.
We combined all of these categories into three overall risk levels: low risk (green, yellow, and light purple), high risk (orange, red, and dark purple) and unknown risk (white). The low risk group includes people who might be in earlier stages of CKD, and the high risk group includes people who might be in later stages of CKD. We were not able to determine how advanced the disease is in people in the unknown risk group (white) because of lack of laboratory data and thus have no information about the impairment of kidney function.
For more information on how the heat map was developed for this project, and a table illustrating the modified categories, see the section titled Risk of progression to ESKD in the deliverable.
- Estimated Glomerular Filtration Rate (eGFR)
- Shared Health Diagnostic Services (SHDS) - Chemistry Data
- Chartier M, Dart A, Tangri N, Komenda P, Walld R, Bogdanovic B, Burchill C, Koseva I, McGowan K-L, Rajotte L. Care of Manitobans Living with Chronic Kidney Disease. Winnipeg, MB: Manitoba Centre for Health Policy, 2015. [Report] [Summary] [Updates and Errata] [Additional Materials] (View)
- Kidney Disease Improving Global Outcomes (KDIGO). KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. 2013. Available from. [Report] (View)
Manitoba Centre for Health Policy
Community Health Sciences, Max Rady College of Medicine,
Rady Faculty of Health Sciences,
Room 408-727 McDermot Ave.
University of Manitoba
Winnipeg, MB R3E 3P5 Canada