CKD Controversy: how expanding definitions are

Report
Debate: The expanding definition of
CKD is unnecessarily labelling many
people as diseased
Pro: Andy Stein
Con: Dan Ford
Chair: Prof. Higgins
Tuesday, 5th November 2013, 1-2pm
CSB Room 00067
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
1.
2.
3.
4.
eGFR declines with age and is therefore “normal”
Early identification does not prevent ERF
Labelling people with “CKD” is a burden to the patient
Labelling people with “CKD” is a burden to the nephrologist
and GP
5. Chronic Kidney Disease is not really a Disease
1.
eGFR declines with age and is therefore
“normal”
1.
eGFR declines with age and is therefore
“normal”
• Longitudinal studies of kidney function.
– 33-41% of patients showed no decline
• It may be statistically “normal”
• It is no more physiologically normal than coronary
atherosclerosis
Baltimore longitudinal study of ageing. Lindeman J Am Geriat Soc 1985;33(4):278-85
Progression of kidney dysfunction in the community-dwelling elderly. Hemmelgarn KI 2006;69:2155-61
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
1.
2.
3.
4.
eGFR declines with age and is therefore “normal”
Early identification does not prevent ERF
Labelling people with “CKD” is a burden to the patient
Labelling people with “CKD” is a burden to the GP and
nephrologist
5. Chronic Kidney Disease is not really a Disease
2.
Early identification does not prevent ERF
• Early identification
– Allows management of complications of CKD
– Prevents progression of CKD
– Reduces late presentation
• Higher mortality, morbidity, hospital stay,
cost (£30,000/year)
• Due to poorer clinical state at
presentation, lack of vascular access
• No possibility of pre-emptive
transplantation
• Poor psychological preparation
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
1. eGFR declines with age and is therefore “normal”
2. Early identification does not prevent ERF
– CKD is not just about preventing ERF
– Clear association between CKD education (KDOQI, NICE, eGFR, QoF)
and reduction in late presentation (~700 patients/year)
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
1.
2.
3.
4.
eGFR declines with age and is therefore “normal”
Early identification does not prevent ERF
Labelling people with “CKD” is a burden to the patient
Labelling people with “CKD” is a burden to the GP and
nephrologist
5. Chronic Kidney Disease is not really a Disease
3. Labelling people with “CKD” is a burden to the
patient
3. Labelling people with “CKD” is a burden to the
patient
38: Samal et al. Routine dipstick screening
27: Crinson et al. Qualitative exploration of GP perspectives
3. Labelling people with “CKD” is a burden to the
patient
38: Samal et al. Routine dipstick screening
27: Crinson et al. Qualitative exploration of GP perspectives
24: Spence: a bit of a rant in the BMJ
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
?
1. eGFR declines with age and is therefore “normal”
2. Early identification does not prevent ERF
3. Labelling people with “CKD” is a burden to the patient
– Evidence presented is poor
– Population at minimal risk of progression or complications of CKD (i.e.
>70 years with stable eGFR 45-59) has already been addressed by NICE
in 2008
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
1.
2.
3.
4.
eGFR declines with age and is therefore “normal”
Early identification does not prevent ERF
Labelling people with “CKD” is a burden to the patient
Labelling people with “CKD” is a burden to the nephrologist
and GP
5. Chronic Kidney Disease is not really a Disease
4. Labelling people with “CKD” is a burden to the GP
and nephrologist
Nephrologist
4. Labelling people with “CKD” is a burden to the GP
and nephrologist
GP
– QOF
• Register of patients with CKD
• BP monitoring & control
• Monitoring of uACR
– Most with CKD 3:
• IHD, DM, HTN, vascular disease
• Already in “cardio-vascular” registers/clinics/QoFs
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
?
1.
2.
3.
4.
eGFR declines with age and is therefore “normal”
Early identification does not prevent ERF
Labelling people with “CKD” is a burden to the patient
Labelling people with “CKD” is a burden to the nephrologist
and GP
The expanding definition of CKD is unnecessarily
labelling many people as diseased: Summary
?
1.
2.
3.
4.
eGFR declines with age and is therefore “normal”
Early identification does not prevent ERF
Labelling people with “CKD” is a burden to the patient
Labelling people with “CKD” is a burden to the nephrologist
and GP
5. Chronic Kidney Disease is not really a Disease
5. Chronic Kidney Disease is not really a
Disease
1. a disordered or incorrectly functioning organ, part, structure,
or system of the body
2. any harmful, depraved, or morbid condition
Is CKD associated with dysfunction or harm?
• Reduced GFR
• Albuminuria
– Are both, independently, associated with
increased mortality
Nitsch D et al. BMJ 2013;346:bmj.f324
Summary:
Burden of CKD guidelines
1.
2.
?
3.
4.
5.
eGFR declines with age and is
therefore “normal”
Early identification does not
prevent ERF
Labelling people with “CKD” is a
burden to the patient
Labelling people with “CKD” is a
burden to the GP and
nephrologist
Chronic Kidney Disease is not
really a Disease
Benefits of CKD guidelines
• Reduced progression in small but
significant numbers who progress
to ERF
• Reduction in late presentation to
dialysis
• Awareness of CKD
– CVS risk management
– Monitor for progression
The expanding definition of CKD is unnecessarily
labelling many people as diseased: No
•
•
•
•
CKD is pathological, not statistically normal
CKD is truly prevalent
CKD is manageable
A CKD label is a minimal burden to a patient provided it is
communicated well
• ERF is rare but harmful, burdensome and preventable
• CKD guidelines have done considerably more good than harm
Thank you
“CKD Controversy: how expanding definitions are unnecessarily labelling
many people as diseased”
Moynihan R et al, BMJ 2013; 347
Dr Andrew Stein
Consultant in Renal and Acute Medicine
Ebers Papyrus (1550 BC)
Why do new ‘diseases’ occur?
•
Some are genuinely new, eg
– Bugs evolve
– Humans evolve
– Planet changes
•
Or, ‘created’ by confusion between
causation and association .. and
drug and technology industries,
fuelling the capitalist dream (taxes,
growth etc)
CKD/eGFR a new disease?
• Is it a new disease? No
• Is it a disease? No
• What is it?
• Is it a good thing even if its all made up?
3 Possible Equations for eGFR
• GG = (140-Age) x weight (in kg)]/72 x
Serum creatinine (in mg/dL)*
• MDRD = 32788 x sCr (mmol/L)-1.154 x
age-0.203 x [1.212 if black] x [0.742 if
female]
• CKD-EPi = 141 x min(sCr/k,1)a x
max(sCr/k,1)-1.209 x 0.993age x (1.018 if
female) x (1.159 if black)
So, how common
is CKD?
Age-specific prevalence of
CKD. Prevalence of CKD
for each age group by
gender in 10,063
participants of the Tehran
Lipid and Glucose Study
(TLGS). Hosseinpanah et
al. BMC Public Health
2009 9:44
Choices
•
•
•
Is Dan right?
Ie, 60% pop > 70y have kidney
failure
Or not?
Consequences of Adoption of eGFR/CKD concept
• The adoption of this definition has
resulted in more than 1 in 8 adults
(almost 14%) in the US being labelled as
having CKD
• And as many as 1 in 6 adults in Australia
Levey AS, Coresh J. Chronic kidney disease. Lancet 2012;379:165-80
Chadban SJ, Briganti EM, Kerr PG, Dunstan DW, Welborn TA, Zimmet PZ, Atkins RC.
Prevalence of kidney damage in Australian adults: the AusDiab kidney study. J Am Soc
Nephrol 2003;14(suppl 2):S131-8
100 consecutive UHCW medical take patients
(Oct 2012)
AKI/CKD
44%
No
AKI/CKD
56%
What Happens to patients with CKD (not much)
• Norwegian study (2006) surveyed 65,000
members of the general population with a
median age of 49
• Less than 1% of people with an eGFR of 4559 ml/min/1.73 m2 (stage 3A disease) went
on to develop end stage renal disease after
eight years of follow-up
Hallan SI, Dahl K, Oien CM, Grootendorst DC, Aasberg A, Holmen J, Dekker FW.Screening
strategies for chronic kidney disease in the general population: follow-up of cross sectional
health survey BMJ 2006;333:1047.
Risk Factors not Diseases
•
•
•
•
•
Pre-diabetes
Hypertension
Hypercholesterolaemia
Obesity
CKD?
Two ambiguities:
– Causation and association
– Is the carrier of a (possibly genetic) predisposition ill or not?
What is kidney failure?
Why Does Overdiagnosis Occur?
• Screening
• Increasingly sensitive tests (D-dimer)
• Incidentalomas (things picked up on CT for
another reason)
• Widened definitions (‘pre-diabetes’)
• Confusion between causation and
association (CKD)
Who developed this concept?
• Kidney Disease Outcomes Quality Initiative
under the auspices of the US National Kidney
Foundation (2002)
• The guideline that launched the framework
was supported by a pharmaceutical company
• “In the face of confusion and criticism of the
potential for the framework to lead to
overdiagnosis, specialist international
meetings were held in 2004, 2006, and 2009
to discuss modifications”
Other Diseases are Overdiagnosed
(Hint: some may not exist)
•
•
•
•
•
•
•
•
•
•
•
Asthma — Canadian study suggests 30% of people with diagnosis may not have asthma, and 66%
of those may not require medications
Attention deficit hyperactivity disorder — Widened definitions have led to concerns about
overdiagnosis; boys born at the end of the school year have 30% higher chance of diagnosis and
40% higher chance of medication than those born at the beginning of the year
Breast cancer — Systematic review suggests up to a third of screening detected cancers may be
overdiagnosed
Gestational diabetes — Expanded definition classifies almost 1 in 5 pregnant women
High blood pressure — Systematic review suggests possibility of substantial overdiagnosis
High cholesterol — Estimates that up to 80% of people with near normal cholesterol treated for life
may be overdiagnosed
Lung cancer — 25% or more of screening detected lung cancers may be overdiagnosed
Osteoporosis — Expanded definitions may mean many treated low risk women experience net
harm
Prostate cancer — Risk that a cancer detected by prostate specific antigen testing is
overdiagnosed may be over 60%
Pulmonary embolism — Increased diagnostic sensitivity leads to detection of small emboli. Many
may not require anticoagulant treatment
Thyroid cancer — Much of the observed increase in incidence may be overdiagnosis
Attention deficit hyperactivity
disorder
• Diagnoses of children with ADHD have
increased++, as have prescriptions for
drugs to control it
• Are they badly behaved children whom
parents and schools cannot control
• Or, do children behave badly because they
have a disease that requires
pharmaceutical intervention?
Osteoporosis and Homosexuality – Diseases?
•
•
•
•
•
Osteoporosis, which after being officially recognised as a
disease by the WHO in 1994, switched from being an
unavoidable part of normal ageing to a pathology
Homosexuality has travelled in the opposite direction through
medical territory, and out the other side
Redefined during the 19th century as a state rather than an act
In the first half of the 20th it was viewed as an endocrine
disturbance requiring hormonal treatment
Later its pathological identity changed as it was re-categorised
as an organic mental disorder treatable by electroshock and
sometimes neurosurgery; and finally in 1974 it was officially depathologised, when the American Psychiatric Association
removed it from the list of disease states in the Diagnostic and
Statistical Manual IV
What would convince me of eGFR/CKD thing?
1. “The incidence of the disease should increase in relation to
the duration and intensity (dose) of the suspected factor
2. The distribution of the suspected factor should parallel that of
the disease in all relevant aspects
3. A spectrum of illness should be related to exposure to the
suspected factor
4. Reduction or removal of the factor should reduce or stop the
disease”
Lilenfeld, A. M., On the methodology of investigations of etiologic
factors in chronic disease. Some comments. J. Chronic Dis.
10, 41 (1959)
So what is eGFR/CKD thing?
•
•
•
•
•
•
•
•
A new disease? No
A disease? No
A confusion between causation and association? Yes
A concept created with the best of intentions? Yes
Fuelled by the drug and technology industries? Yes
A risk factor? Possibly
A genetic predisposition? Possibly
A ’good thing’? Possibly
If you go looking for Zebras ..
Thankyou!

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