Public Health Screening Flashcards
The presumptive identification of an unrecognized disease or defect by the application of tests, examinations
Screening
TRUE OR FALSE: Screening is definite
FALSE, it is only presumptive, not diagnostic and not confirmatory
TRUE OR FALSE: Screening is done to test symptomatic individuals to reduce severity of disease.
FALSE, asymptomatic individuals at an earlier stage in the natural history of disease.
Screenings falls under what level of prevention?
Secondary
____ is done for people with symptoms as a confirmatory test
Early diagnosis
Screening aims to reduce which of the following
A. Mortality, Incidence, MMR
B. Mortality, Incidence, Prevalence
C. Mortality, Incidence, Severity
C. Mortality, Incidence, Severity
Types of Screening
- Mass Screening
- Targeted Screening
- Case-finding or opportunistic screening
- Multiple or Multiphasic Screening
Screening applied to the general/whole/entire
population or a large subset
Mass screening
Screening applied to high risk groups or groups with specific exposures or risk factors
Targeted Screening
Screening aimed to patients who sought consult for some other purpose
Case-finding or opportunistic Screening
Screening which uses several screening tests at the same time to detect severalconditions
Multiple or Multiphasic Screening
What is the criteria for diseases appropriate for screening?
- Disease is serious with severe consequences
- Treatment is more effective at an earlier stage
- Disease has a detectable preclinical phase
- Detectable preclinical phase is fairly long and prevalent in target population
Characteristics of a screening test
- Economical
- Convenient
- Relatively free of risk and discomfort
- Acceptable to a large number of individuals
- Highly valid and reliable
Reliability is also referred to as ____
Precision
Reliability is influenced by:
- Stability
- Technical characteristics
- Interobserver and intraobserver
_______ are burdens on the healthcare system
False positive
PPV increases with ____
Prevalence
In evaluating a screening program, what is the criteria?
- Feasibility
- Effectiveness
Factors of Screening programs
- Acceptability
- Cost-effectiveness
- Provision for follow-up diagnosis and treatment of test-positive individuals
- Yield of Cases
The customary way to evaluate the success of a screening program is to compare _______
survival experience
Potential systematic errors which may affect effectiveness
- Lead-time bias
- Length bias
- Volunteer Bias
Bias that appears when survival may appear longer among screened individuals simply because their diagnoses were made earlier
Lead-time Bias
Lead time ______ the benefit of screening
(Over/Under)estimates
Overestimates
Occurs when screening tends to identify cases with less aggressive forms of the disease
Length-bias sampling
Volunteer Bias occurs only in ______
observational studies
Two types of multiple screening tests
- Sequential (Serial) testing
- Simultaneous (Parallel) Testing
Serial testing increases ______
Overall specificity
Multiple screening test where those who tested positive for the first test will be subjected to the second test
Sequential
Parallel testing increases ____
Overall sensitivity
