Week 7 Screenings Flashcards
Screening
- detection of a disease in its early stages
- treat the disease, stop the disease from progressing
- also reduce cost of disease management by avoiding costly interventions required at later stages
Early Detection
key
- some diseases preceded by a period of asymptomatic pathogenesis or latency
- can be simple and inexpensive compared to the burden of disease
- avoids more intensive intervention later
Individual Screening
- one person tested
- often chosen based on risk factors
- sometimes chosen based on universal screening
- mammogram for young adult who has family hx of breast cancer
Group or mass screening
target population selected on basis of increased risk
- vision screening in school children
- testing for PKU in neonates
One-test disease specific screening
- single test
- detects characteristic indicating high risk
- Hemoglobin A1C and diabetes
- Cholesterol levels and hypercholesterolemia
Multiple test screening
2 or more tests to detect one disease
- tuberculosis = tb skin test, blood test, chest x-ray, sputum cultures
- if one comes back positive, then they do more
Screening Criteria
- detection
- diagnostic criteria
- screening measures
Detection
- for a certain disease, are there well-documented diagnostic criteria?
- Resources/treatment that are available to support that screening?
Diagnostic criteria
- disease should have early asymptomatic state, if not should we be screening for it?
- risk factors: who should be screened?
Screening measures
- must be safe, cost-effective, accurate
- screening tool must accurately distinguish those with and without disease
Advantages of Screening
- simple screening tests are cost-effective
- screening process can be applied to both individuals and larger populations (like BP check at appt or fairs)
- some screenings mandated by law (ex. PKU)
- screening can be one test disease specific or multiple test screening
- creates opportunity for health teaching
Disadvantages of screening
- uncertainty in scientific evidence/possibility of errors
- any margin of error can have serious consequences
- false positive = anxiety, unnecessary interventions
- false negatives = disease is overlooked, missed opportunity for early intervention, provide false assurance
- ex = microcalcification on mammogram leads to painful biopsy
Selection of a “screenable” disease
- just because we can, does it mean we should
- Consider the following q’s =
- Does its significance warrant its consideration as a community problem?
- Does it affect multiple people? Rare?
- Can the disease be detected by a screening?
- Should screening for the disease be done? Like if we don’t have treatment for it
- Health benefits: can it be treated?
- Tangible and intangible costs (emotional and financial)
Answers = complex and ethical
Should screening be done?
- Is there any benefit to early detection?
- Are there effective treatments available?
Interventions/treatment modalities
- specific interventions that will affect disease progression needed to justify screening
- f/u critical to aid implementing interventions
- consider safety = avoid risks or harmful effects
- some screenings are not recommended due to false positives and overtreatment
- USPSTF = may recommend against screening, where the guidelines come from
Quality of Life
subjective, difficult to assess
- some formulas for calculating
Epidemiology
method used to find cause of disease (and outcomes) in populations
Morbidity
diseased state or disability from any cause
- includes range or degree of illness
Rate?
Mortality
deaths in a given population as a result of a specific disease/illness/event
Significance
level of priority of disease as public health concern
Incidence
rate of a new population problem and estimates risk of individual developing disease
- measures new cases
rate of a new population problem, risk of individual developing disease ACUTE
IN = incidence and new
Prevalence
proportion of the population with disease at any one point in time
- measures all cases within a set period of time
proportion of population with disease at any given one point in time
CHRONIC
CP = current and prevalence
Screening Measues
Reliable ≠ Valid
Reliability
Extent to which a measuring procedure yields consistent results on repeated administrations of the scale
- exact same results every time
Inter-observer
same results when 2 persons do test
Intra-observer
same person able to reproduce results in same pt
Validity
Degree that a measuring procedure accurately reflects, assess, or captures the specific concept that the researcher is attempting to measure
- measuring what you actually want to measure
measurement of accuracy, is the test able to distinguish who has the disease
Test sensitivity
the ability of a test to correctly identify those with the disease (true positive rate)
- if you do have the disease, you would have true positive
Test specificity
the ability of a test to correctly identify those without the disease (true negative rate)
- if you don’t have a disease, you would want a true negative
Guidelines
come from USPSTF
- change over time
Ethical considerations
request for participation implies a health benefit
- ethical and economic
Clinical preventative services
- save years of life and help people live better during those years
- save money, provide quality care, reduce death, disability, and disease
USPSTF
panel of experts in primary care and prevention who reviews the evidence of effectiveness and develops recommendations for clinical prevention services
- 16 categories in their guide to clinical preventive services
USPSTF Grading
A B C D I
Grading = A
- recommends the service
- high certainty that the net benefit is substantial
- offer or provide this service
Grading = B
recommends this service
- high certainty that net benefit is moderate or there is moderate certainty that the net benefit is moderate or substantial
- offer or provide this service
Grading = C
- recommends selectively offering or providing this service to individual patients based on professional judgement and pt preference
- there is at least small to moderate certainty that the net benefit is small
- offer or provide this service for selected patients depending on individual circumstances
Grading = D
- recommends against this service
- moderate or high certainty that the service has no net benefit or that the harms outweigh the benefit
- Discourage the use of this service
Grading = I
- concludes that the current evidence is insufficient to assess the balance of benefits and harms of the service
- evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined
- pt’s should be aware of the uncertainty about the balance of benefits and harms, if the service is offered
Nursing role in screening
- development and implementation of screening programs
- decision maker
- planner
- education and counseling
- follow up
- collaborate with other HCPs
- focus on primary and secondary prevention
