Secondary & Tertiary prevention (lesson8)
DEFINITION OF WHAT IS SECONDARY 1 AND TERTIARY PREVENTION2
SECONDARY PREVENTION
- Target group: individuals or groups with known risk factors.
- Goal: prevent the development of social, behavioral, emotional, or physical disorders.
- Approach:
• Early identification of at-risk individuals.
• Application of evidence-based interventions.
- Objectives:
• Lower the prevalence of disorders.
• Ameliorate symptoms.
• Reduce the duration of disorders.
• Increase protective factors to enhance resiliency
when exposed to risks.
Secondary prevention: Detection and
treatment of pathological processes early.
Intervention at this point can be more
effective (when not at risk, e.g. age
groups for cancer screening).
Tertiary prevention: Chronic disorder, how
you cope with certain kind of illness.
SECONDARY PREVENTION INVOLVES PROCEDURES TO DETECT AND ARREST PRE-CLINICAL
PATHOLGICAL CHANGES
Primary: this can be risk factors
Secondary: testing for levels for insulin (screening)
Tertiary: they have the problem and you need to deal
with it (from diagnosis one switches to tertiary
prevention)
1
Secondary prevention: interventions targeting individuals and groups who, because of known risk factors, are
vulnerable to developing social, behavioral, emotional, or physical disorders.
2
Tertiary prevention: strategies to reduce the impact of an ongoing illness or injury.
, CRITICAL CONSIDERATIONS ABOUT SECONDARY PREVENTION
(What is meant by screening, how to measure the effectiveness of the screening, when should screening
be performed.)
SCREENING- WHO CRITERIA
- The screening programme should respond to a recognized need.
- The objectives of screening should be defined at the outset.
- There should be a defined target population.
- There should be scientific evidence of screening programme effectiveness.
- The programme should integrate different approaches to promote it: education, testing, clinical services,
and programme management.
- There should be quality assurance, with mechanisms to minimize potential risks of screening.
- The programme should ensure informed choice, confidentiality, and respect for autonomy.
- The programme should promote equity and access to screening for the entire target population.
- Programme evaluation should be planned from the outset.
- The overall benefits of screening should outweigh the harm.
Key questions:
- How effective is the screening instrument? (Includes false positives and false negatives)
- Does early intervention lead to better outcomes?
- What is the cost/effectiveness?
- What are the negative aspects of screening?
SCREENING METRICS
Metric Definition Formula TP= true positive (cf. have disease, positive result)
TN= true negative (cf. haven’t disease, negative result)
Sensitivity True positive rate: How well TP / (TP + FN) FP= false positive (cf. haven’t disease, but positive result)
the disease is identified. FN= false negative (cf. have disease, but negative result)
Specificity True negative rate: How well TN / (FP + TN)
the non-sick are identified.
Positive and negative predictive value: Screening interventions are adjusted based on the
Metric Meaning Formula screening values (e.g., sensitivity, specificity, PPV,
Positive Predictive How sure I am about a TP / (TP + FP) NPV). These values help decide whether to target
Value (PPV) positive result specific age groups.
Negative Predictive How sure I am about a TN / (TN + FN) Purpose: to understand how well the screening tool
Value (NPV) negative result performs in practice.
PREDICTIVE BIOMARKERS3
The method used to test the predictive biomarker is crucial.
HOW TO IDENTIFIED
- Randomized control trails: Condition with & without biomarker => compare
- Longitudinal studies (pre-registration): Focus on certain parameters, are they predictive for a
certain disease over time?
3
Predictive biomarkers: identified when its presence or change indicates that an individual or group is more likely
to experience a favorable or unfavorable effect from: medical product or environmental agent.
DEFINITION OF WHAT IS SECONDARY 1 AND TERTIARY PREVENTION2
SECONDARY PREVENTION
- Target group: individuals or groups with known risk factors.
- Goal: prevent the development of social, behavioral, emotional, or physical disorders.
- Approach:
• Early identification of at-risk individuals.
• Application of evidence-based interventions.
- Objectives:
• Lower the prevalence of disorders.
• Ameliorate symptoms.
• Reduce the duration of disorders.
• Increase protective factors to enhance resiliency
when exposed to risks.
Secondary prevention: Detection and
treatment of pathological processes early.
Intervention at this point can be more
effective (when not at risk, e.g. age
groups for cancer screening).
Tertiary prevention: Chronic disorder, how
you cope with certain kind of illness.
SECONDARY PREVENTION INVOLVES PROCEDURES TO DETECT AND ARREST PRE-CLINICAL
PATHOLGICAL CHANGES
Primary: this can be risk factors
Secondary: testing for levels for insulin (screening)
Tertiary: they have the problem and you need to deal
with it (from diagnosis one switches to tertiary
prevention)
1
Secondary prevention: interventions targeting individuals and groups who, because of known risk factors, are
vulnerable to developing social, behavioral, emotional, or physical disorders.
2
Tertiary prevention: strategies to reduce the impact of an ongoing illness or injury.
, CRITICAL CONSIDERATIONS ABOUT SECONDARY PREVENTION
(What is meant by screening, how to measure the effectiveness of the screening, when should screening
be performed.)
SCREENING- WHO CRITERIA
- The screening programme should respond to a recognized need.
- The objectives of screening should be defined at the outset.
- There should be a defined target population.
- There should be scientific evidence of screening programme effectiveness.
- The programme should integrate different approaches to promote it: education, testing, clinical services,
and programme management.
- There should be quality assurance, with mechanisms to minimize potential risks of screening.
- The programme should ensure informed choice, confidentiality, and respect for autonomy.
- The programme should promote equity and access to screening for the entire target population.
- Programme evaluation should be planned from the outset.
- The overall benefits of screening should outweigh the harm.
Key questions:
- How effective is the screening instrument? (Includes false positives and false negatives)
- Does early intervention lead to better outcomes?
- What is the cost/effectiveness?
- What are the negative aspects of screening?
SCREENING METRICS
Metric Definition Formula TP= true positive (cf. have disease, positive result)
TN= true negative (cf. haven’t disease, negative result)
Sensitivity True positive rate: How well TP / (TP + FN) FP= false positive (cf. haven’t disease, but positive result)
the disease is identified. FN= false negative (cf. have disease, but negative result)
Specificity True negative rate: How well TN / (FP + TN)
the non-sick are identified.
Positive and negative predictive value: Screening interventions are adjusted based on the
Metric Meaning Formula screening values (e.g., sensitivity, specificity, PPV,
Positive Predictive How sure I am about a TP / (TP + FP) NPV). These values help decide whether to target
Value (PPV) positive result specific age groups.
Negative Predictive How sure I am about a TN / (TN + FN) Purpose: to understand how well the screening tool
Value (NPV) negative result performs in practice.
PREDICTIVE BIOMARKERS3
The method used to test the predictive biomarker is crucial.
HOW TO IDENTIFIED
- Randomized control trails: Condition with & without biomarker => compare
- Longitudinal studies (pre-registration): Focus on certain parameters, are they predictive for a
certain disease over time?
3
Predictive biomarkers: identified when its presence or change indicates that an individual or group is more likely
to experience a favorable or unfavorable effect from: medical product or environmental agent.
