Monitoring and Screening
HINF 371 - Medical Methodologies
Session 10
Objective
Understand the function of screening
and monitoring in the continuum of
disease progression
 Understand the factors in deciding for
screening and monitoring

Reading


Mar CD, Doust J, Glasziou (2006) Chapter 7:
Monitoring in Chronic Disease, Blackwell Publishing
and BMJ Books, USA
Mar CD, Doust J, Glasziou (2006) Chapter 8:
Screening for disease, health promotion and
disease prevention, Blackwell Publishing and BMJ
Books, USA
Quick discussion about
assignment types possible
1.
2.
3.
4.
Current structure – questions and
answers (4 of them)
Introduction of a case and development
of the decision (one of two assignments
for the term)
Data given for a health region and
decisions for program development
(single assignment for the term)
Student presentations of topics
(considered one assignment)
Prevention and Screening

Aim is to reduce the risk of death and morbidity by
reducing the exposure to risk factors for disease before
the process even starts (health promotion) or by
providing interventions that prevent the disease from
ever manifesting (disease prevention) – primary
prevention
Levels of Prevention
Activity
What it does
Examples
Health promotion
Interventions that
generally improve health
for everyone
Exercise, stop smoking,
eating well
Disease prevention
Pre-emptively acting
before a specific disease
manifests
Vaccination, Seat belts,
cycle helmets
Disease screening
Look signs of disease
before they manifest
Mammography, BP
measurement, cervical
screening
Anticipatory care
Looking for, and
anticipating complications
of a disease
Db (retinopathy,
micovascular damage,
neuropathy), CHF (acute
crisis, adherence to drugs,
diet,exercise)
Screening


Preferred - Pre-test probability is high and test is
highly sensitive
Decision criteria for development





the disease important?
there an effective test?
there an effective treatment?
the test affordable and acceptable?
Decision criteria for use




Is
Is
Is
Is
Is the effective treatment more effective in early stages?
Do benefits outweigh harms?
Is the test routinely available?
Examples: Cervical cancer, prostate cancer, stroke,
PKU, Lung Cancer
Selection of Population to
Target


High risk groups or all groups
High risk groups





Exposure to the risk factor is more limited within the population
Where susceptibility following exposure to the risk factor is
limited, or where there is a threshold effect
Where it is easier or cheaper to identify persons at high risk
Intervention is difficult to comply with or carries a significant
risk of side effects
All groups



The target disorder is common and a large proportion of the
population is exposed to risk factors for target disorder
Where the risk of disease rises continuously with exposure to
the risk factor (as occurs with blood pressure and cholesterol
levels)
Where it is easier or cheaper to apply an intervention to an
entire population than to find and direct the interventions to
individuals at high risk of the target disorder
Monitoring
Periodic measurement followed by
adjustment of the management
 External homeastasis
 Clinical effectiveness versus
opportunity cost

When to monitor
What are the short-term
consequences?
 What are the long term
consequences?
 Do symptoms give early warning?

Phases of Monitoring
Pre-treatment (to diagnose)
 Initial titration

Pharmacokinetics
 Pharmacodynamics


Maintenance
One recording above 3 SD
 Two recordings above 2 SD

Re-establish control
 Cessation

Which Measurement

Is it a good measure of clinically relevant
outcomes?


Can it detect changes in risk rapidly
enough?



Proximal targets versus distal targets
“Most relevant outcome that can be assessed
reasonably soon”
Is the random variability acceptable, or can
it be made acceptable by repeated
measurements?
Is it sufficiently affordable, accessible, and
acceptable to patients?
Can it detect changes in risk
rapidly enough?
Patient adherence drug concentration  markers
of bone turnover  bone mineral density 
asymptomatic factures  symptomatic fractures
Patient Monitoring
For
 For
 For
 For

reporting to physician
improving the adherence
early warning
treatment adjustments?
Common Errors in Monitoring
Re-checking too soon
 Over-reacting to changes
 Over-adjusting therapy

STABLE HEALTH
Reminders,
Goal Setting,
Action
Planning
UNSTABLE HEALTH
INABILITY TO SELF
MANAGE
Transitional
Care
Case
Managers
Telemonitoring
END-OF-LIFE
(First Admission
Planned Admissions
Readmissions)
Acute Care
Treatment
Discharge
Plan.
Transitional
Care
Acute Care
Treatment
Discharge
Plan.
Transitional
Care
Acute Care
Treatment
Discharge
Plan.
Transitional
Care
Acute Care
Treatment
Discharge
Plan.
Transitional
Care
Acute Care
Treatment
Discharge
Plan.
Transitional
Care
Palliative Care
Case Management
Specialized Clinic Support
Monitoring and Care Coordination
Primary and Secondary Prevention
Family Physician and Specialist Care
OBJECTIVE
Prevent or limit
deterioration of the
health of patients
with CHF
Treatment of Acute Episode with minimal
deteriation in function and general health
INDICATOR
Supported Self-Care and Pharmaceutical Therapy
Prevent risk factors that
cause Heart Failure
Reduction in incidence
and prevalence of HF
Longer time from
diagnosis to
unstable disease
Longer time from
diagnosis or unstable
disease to first urgent
hospital admission
PT. JOURNEY
© VCHA 2007, Jiwa & Yazganoglu
REQUIRED CARE
ENABLERS
PRE-HEART FAILURE
HF Risk
Factors
Diagnosis
HF
Diagnoses
Unstable
Disease
Increased time between unplanned hospital
admissions, Reduced number of hospital
admissions, shorter length of stay
First
Hospital
Admission
Hospital
Admission
Loss of Ability Hospital
to Self-Care Admission
Decision to
End Life