Post on 20-Jan-2016
Advanced CKD Study
Daniel FordUKRR Annual Audit Meeting
June 2009
Overview
Data collection issues– Definition of the date of start of dialysis
Pre-RRT study results– Associations with the rate of kidney function
decline in the final year pre-RRT
Pre-RRT Study
ObjectivesTo look at what factors are associated with:– eGFR decline– Hb decline– Survivalduring the final year prior to starting RRT
Methods4,722 incident RRT patients from 7 centres from 2001-2006Extracted laboratory data– 0, 1, 2, 3, 4, 5, 6, 12 months pre-RRT
Median eGFR pre-RRT (Centre 4)- (IQRs)
0
2
4
6
8
10
12
14
16
-15 -12 -9 -6 -3 0
Time pre-RRT (months)
eG
FR
(m
l/min
/1.7
3m
2)
.
Proportion of patients excluded from study because of anomalous timeline data
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
a b c d e f g h i
Centre
Nu
mb
er
of
pa
tien
ts
Excluded
Included
Proportion of patients excluded from study because of anomalous timeline data
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
a b c d e f g h i
Centre
Nu
mb
er
of
pa
tien
ts
Excluded
Included
n=826
• Distinction between “acute” and “chronic” HD• Definition of start of PD
Definition of “acute HD”
Of 826 records checked, 14.9% started RRT on “acute” HD with no retrospective timeline change
Definition of “acute HD”
“If a patient started as ‘acute’ renal failure and did not recover, the date of start of renal replacement should have been backdated to the start of acute dialysis.”
Definition of “acute HD”“If a patient started as ‘acute’ renal
failure and did not recover, the date of start of renal replacement should have been backdated to the start of acute dialysis.”
• Appendix B of Annual Report (online only)
• Methodology or instruction to clinicians?
Definition of start of PD
• 75/826 had some evidence of PD exchanges prior to documented start date
• What is the date of start of PD?
Definition of start of PD
• 75/826 had some evidence of PD exchanges prior to documented start date
• What is the date of start of PD?– Insertion of PD catheter?– First fluid exchange after PD catheter?– Date of start of CAPD training?– Date of PD independence?
Consequences of inaccurate RRT start date
• Dubious eGFR trend pre-RRT
• Existing eGFR at start studies
• Survival data• Late presentation
data
Median eGFR pre-RRT (Centre 4)- (IQRs)
0
2
4
6
8
10
12
14
16
-15 -12 -9 -6 -3 0
Time pre-RRT (months)
eG
FR
(m
l/min
/1.7
3m
2)
.
What needs to be done?
• UKRR– Redefine date of start of HD (acute/chronic)
• National– Consensus on date of start of PD
ISSN 1471-3349
The Renal Association
UK Renal Registry
The Eleventh Annual Report
December 2008
This report was prepared by Dr David Ansell, Professor John Feehally, Dr Damian Fogarty,
Dr Daniel Ford, Dr Alex Hodsman, Dr Charles Tomson, Dr Udaya Udayaraj, Dr Graham Warwick and Dr Andrew Williams
in association with F Caskey, K Farrington, R Fluck, M Lewis,
J Nicholas, R Ravanan, D Richardson and D Thomas
Date of start of HDIf a patient started as ‘acute’ renal
failure and did not recover, the date of start of renal replacement should have been backdated to the start of acute dialysis. Many nephrologists do not do this and where this period of acute dialysis has been recorded in local systems, the UKRR will use this data to backdate the start of RRT.
Appendix B UKRR 11th Annual Report, December 2008
ISSN 1471-3349
The Renal Association
UK Renal Registry
The Eleventh Annual Report
December 2008
This report was prepared by Dr David Ansell, Professor John Feehally, Dr Damian Fogarty,
Dr Daniel Ford, Dr Alex Hodsman, Dr Charles Tomson, Dr Udaya Udayaraj, Dr Graham Warwick and Dr Andrew Williams
in association with F Caskey, K Farrington, R Fluck, M Lewis,
J Nicholas, R Ravanan, D Richardson and D Thomas
Date of start of HDIf a patient started as ‘acute’ renal
failure and did not recover, the date of start of renal replacement should have been backdated to the start of acute dialysis. Many nephrologists do not do this and where this period of acute dialysis has been recorded in local systems, the UKRR will use this data to backdate the start of RRT.
Appendix B UKRR 11th Annual Report, December 2008
Letter to RA membershipC Tomson, M Raftery, 23rd March 2009
ISSN 1471-3349
The Renal Association
UK Renal Registry
The Eleventh Annual Report
December 2008
This report was prepared by Dr David Ansell, Professor John Feehally, Dr Damian Fogarty,
Dr Daniel Ford, Dr Alex Hodsman, Dr Charles Tomson, Dr Udaya Udayaraj, Dr Graham Warwick and Dr Andrew Williams
in association with F Caskey, K Farrington, R Fluck, M Lewis,
J Nicholas, R Ravanan, D Richardson and D Thomas
Date of start of HDIf a patient started as ‘acute’ renal
failure and did not recover, the date of start of renal replacement should have been backdated to the start of acute dialysis. Many nephrologists do not do this and where this period of acute dialysis has been recorded in local systems, the UKRR will use this data to backdate the start of RRT.
Appendix B UKRR 11th Annual Report, December 2008
Letter to RA membershipC Tomson, M Raftery, 23rd March 2009
Date of start of PD
The date of start of peritoneal dialysis is defined as the date of first PD fluid exchange given with the intention of causing solute or fluid clearance
This contrasts with an exchange solely for confirming or maintaining catheter patency. In general, exchanges which are part of PD training should be considered as the start of PD.
ISSN 1471-3349
The Renal Association
UK Renal Registry
The Eleventh Annual Report
December 2008
This report was prepared by Dr David Ansell, Professor John Feehally, Dr Damian Fogarty,
Dr Daniel Ford, Dr Alex Hodsman, Dr Charles Tomson, Dr Udaya Udayaraj, Dr Graham Warwick and Dr Andrew Williams
in association with F Caskey, K Farrington, R Fluck, M Lewis,
J Nicholas, R Ravanan, D Richardson and D Thomas
ISSN 1471-3349
The Renal Association
UK Renal Registry
The Eleventh Annual Report
December 2008
This report was prepared by Dr David Ansell, Professor John Feehally, Dr Damian Fogarty,
Dr Daniel Ford, Dr Alex Hodsman, Dr Charles Tomson, Dr Udaya Udayaraj, Dr Graham Warwick and Dr Andrew Williams
in association with F Caskey, K Farrington, R Fluck, M Lewis,
J Nicholas, R Ravanan, D Richardson and D Thomas
Chapter 7: Survival in UK RRT patients. UKRR 11th Annual Report, December 2008
Summary of timeline issues
Inaccurate timeline returns are common
This has implications for a number of UKRR analyses, including:– Survival– Rates of late presentation– eGFR at start of RRT
This may not be unique to the UKRR
Efforts are being made to re-define and publicise problematic definitions
Pre-RRT Study Results
Pre-RRT study
• 7 centres
• 2001-2006
• n=4,722
• Excluded patients – presenting late (<3m)– with missing data from relevant analyses– with anomalous timeline data– with fewer than 4 eGFR results
eGFR statistical analyses- Retha Steenkamp
• Least-square analysis– Linear regression line fitted on an individual-
patient basis– Mean rate of eGFR decline calculated
• Multi-level model– Quadratic model
Adjusted for:– Age, gender, ethnicity, PRD
Results
• Age
• Ethnicity
• Primary renal disease
• Systolic BP
• Diastolic BP
• Time from first renal presentation
0
1
2
3
4
5
6
7
8
18-34 35-44 45-54 55-64 65-74 75+
Age group (years)
eG
FR
de
clin
e (
ml/m
in/1
.73
m2
/ye
ar)
.
Rate of eGFR decline pre-RRT by age group (adjusted for gender, ethnicity and PRD) (95% CIs)
1. Hunsicker LG, et al. Kidney Int 1997;51:1908-1919. 2. Levin A, et al. American Journal of Kidney Diseases 2008;52:661-671. 3. Eriksen BO, et al. Kidney Int 2006;69:375-382.
Modelled eGFR pre-RRT by age group
6
8
10
12
14
16
18
-15 -12 -9 -6 -3 0Time pre-RRT (months)
eGF
R (
ml/m
in/1
.73m
2)
65-74
75+
Modelled eGFR pre-RRT by age group
6
8
10
12
14
16
18
-15 -12 -9 -6 -3 0Time pre-RRT (months)
eGF
R (
ml/m
in/1
.73m
2)
55-64
65-74
75+
Modelled eGFR pre-RRT by age group
6
8
10
12
14
16
18
-15 -12 -9 -6 -3 0Time pre-RRT (months)
eGF
R (
ml/m
in/1
.73m
2)
45-54
55-64
65-74
75+
Modelled eGFR pre-RRT by age group
6
8
10
12
14
16
18
-15 -12 -9 -6 -3 0Time pre-RRT (months)
eGF
R (
ml/m
in/1
.73m
2)
35-44
45-54
55-64
65-74
75+
Modelled eGFR pre-RRT by age group
6
8
10
12
14
16
18
-15 -12 -9 -6 -3 0Time pre-RRT (months)
eGF
R (
ml/m
in/1
.73m
2)
18-34
35-4445-54
55-6465-74
75+
Rate of eGFR decline pre-RRT by ethnicity (adjusted for age, gender and PRD) (95% CIs)
0
1
2
3
4
5
6
7
8
Asian Black White
eG
FR
de
clin
e (
ml/m
in/1
.73
m2
/ye
ar)
.
1. McClellan W, et al. J Am Soc Nephrol 2006;17:1710-1715. 2. Clase CM, et al. J Am Soc Nephrol 2002;13:1338-1349.3. Coresh J, et al. American Journal of Kidney Diseases 2003;41:1-12. 4. Hsu C-Y, et al. J Am Soc Nephrol 2003;14:2902-2907.
Modelled eGFR pre-RRT by ethnicity (adjusted for age, gender and PRD)
6
8
10
12
14
16
-15 -12 -9 -6 -3 0
Time pre-RRT (months)
eGF
R (
ml/m
in/1
.73m
2)
white
black
asian
Rate of eGFR decline pre-RRT by primary renal disease (adjusted for age, gender and ethnicity) (95% CIs)
0
1
2
3
4
5
6
7
DM GN PKD Pyelo RVD
eG
FR
de
clin
e (
ml/m
in/1
.73
m2
/ye
ar)
1. Hemmelgarn BR, et al. Kidney Int 2006;69:2155-2161. 2. Levin A, et al. American Journal of Kidney Diseases 2008;52:661-671.
3. Jungers P, et al. Nephrol Dial Transplant 1995;10:1353-1360.
Modelled eGFR pre-RRT by primary renal disease (adjusted for age, gender and ethnicity)
4
6
8
10
12
14
16
-15 -12 -9 -6 -3 0
Time pre-RRT (months)
eG
FR
(m
l/min
/1.7
3m
2)
.
DMGN
PyeloPKD
Rate of eGFR decline by systolic BP at 6 months pre-RRT (adjusted for age, gender, ethnicity and PRD) (95% CIs)
0
1
2
3
4
5
6
7
<120 120-139 140-159 ≥160
Systolic blood pressure (mmHg)
eG
FR
de
clin
e (
ml/m
in/1
.73
m2
/ye
ar)
.
Rate of eGFR decline by diastolic BP at 6 months pre-RRT (adjusted for age, gender, ethnicity and PRD) (95% CIs)
0
1
2
3
4
5
6
7
8
9
10
<70 70-79 80-89 90-99 ≥100
Diastolic blood pressure (mmHg)
eG
FR
de
clin
e (
ml/m
in/1
.73
m2
/ye
ar)
.
Rate of eGFR decline pre-RRT by time from first presentation (adjusted for age, gender, ethnicity and PRD)
(95% CIs)
0
2
4
6
8
10
12
<3m 3-6m 6-12m >12m
Time from first renal presentation to starting RRT (months)
eG
FR
de
clin
e (
ml/m
in/1
.73
m2
/ye
ar)
.
Modelled eGFR pre-RRT by time from first renal presentation (adjusted for age, gender, ethnicity and PRD)
6
8
10
12
14
16
18
-15 -12 -9 -6 -3 0
Time pre-RRT (months)
eG
FR
(m
l/min
/1.7
3m
2)
<3m
3-6m
6-12m
>12m
Discussion
Limitations– Retrospective, only includes patients on RRT– Missing data
• Date first seen, PRD, ethnicity, BP, co-morbidity• Timeline issues
Strengths– Largest study of patients in the final year pre-
RRT (4,722 vs. 159 & 342)– Unselected UK incident cohort
1. Jungers P, et al. NDT 1995; 10(8): 1353-60 [n=159]2. Ambrogi V, et al. Nephron Clin Prac 2009; 111: 95-101 [n=342]
Summary of findings
• Associations with faster eGFR decline are:– Younger age– Black and South Asian ethnicity– GN & diabetes– Higher systolic and diastolic BP– Late presentation
Acknowledgements
Statistics
Retha Steenkamp
Supervisors
Damian Fogarty, Yoav Ben-Shlomo, Charlie Tomson, David Ansell
Data collection
David Bull, Andy Webb and the UKRR systems team
UK renal centres and patients