Problems with Prevention:A Clinical Perspective
Michel Accad, MDOctober 17, 2011
GABA Panel Discussion
Cardiovascular Disease• Long latency period• No easily identifiable external signs• Natural history difficult to predict• First manifestation may be benign,
serious or fatal• Tightly connected to aging
Prevention is bound to be difficult
Ann Intern Med 1961
Blood Pressure
LDL Cholesterol
HDL Cholesterol (negative)
Impaired Glucose
Tolerance
Cigarette Smoking Triglycerides
Body Mass Index
C-Reactive Protein Others
Commonly Identified RFs
Disease• Symptoms• Sharp demarcation from
normal• Disease is target for therapy• Deterministic (present or
not)
Risk Factor• Compatible with well-being
over a wide range of values• Continuum of risk • Risk is target for therapy
(risk reduction)• Statistical
Risk Factor≠
Disease
T H ED I S T I N C T I O N
B E T W E E NR I S K F A C T O R
A ND D I S E A S E
H A SB E E N
B L U R R E D
Risk Assessment:A Fluid Concept
• Imperfect Quantitative Models• Doctor’s perspective• Patient’s perspective• Patient’s means
Treating Populations:The Paradox of Prevention
Risk Factors:Disease by fiat
• Cut-off numbers “define” disease
• Numbers selected by super-committees
• Changing cut-off numbers creates millions of patients overnight
Risk factors as disease…
…doctors as weathermen?
118 CVD Risk Factors
And counting…
Risk factor as disease
• The problem of the J-curve
Risk factor
Bad
outc
ome
Public Awareness Campaigns…
(the answer is most certainly yes…)
“It is not the healthy who need a doctor, but the sick.”
Matthew 9:12
Dr. is everything OK?
DO I HAVE
LATENT CVD?
A better approach?
Focus on the early detection
• Atherosclerosis• Hypertensive
Cardiovascular Disease
• Vascular elasticity• Endothelial function• Digital retinal scan• CIMT• Microalbumin• Cardiac stress markers
(eg. BNP)• Vascular calcium• Others
Early detection approach
PROS• Focused on the individual• Not a statistical assessment• Can be monitored in
response to intervention• May identify patients
without risk factors who have CVD
• Facilitates dialogue regarding future risk
CONS• Does not avoid problem of
prediction• Must distinguish disease
patterns from age-related changes in the vasculature
• More expensive• Not “validated”
No longitudinal data
No super committee
endorsement
No reimbursement
by insurance
Limited experience
The conundrum for early detection technologies
A role for the private sector?
The good news for the people
Thank you
Top Related