VS - Right thing to do Flashcards
What is screening?
“Screening” = defined as the detection of pre-symptomatic disease
examination or testing of a group of individuals to separate those who are well from those who have an undiagnosed disease or defect or who are at high risk.
What are the 9 Wilson and Junger criteria for screening?
○ The condition should be an important health problem
○ The natural history of the condition should be understood
○ Should have a recognisable latent stage
○ Should be a test that is; easy to perform, interpret, accurate, acceptable, reliable, sensitive and specific
○ Should be an accepted treatment available for the disease
○ Treatment should be more effective if started early
○ There should be a policy on who to treat
○ Diagnosis and treatment should be cost effective
○ Case finding should be a continuous process
What are some of the ethical issues around screening?
Is the test acceptable to the population (cervical cancer screening and male doctors?)
Some religions believe ‘do no harm’ but some screening tests may involve harm
Describe DS, some features and the change in risk with maternal age:
○ Trisomy 21 - extra copy of chromosome 21 ○ Overall risk 1/1000 pregnancies ○ Dependent on maternal age ○ Prevalence at age 20 = 1/1500 ○ Prevalence at age 30 = 1/900 ○ Prevalence at age 40 = 1/100 ○ Physical and mental features: ○ Learning difficulties ○ Congenital heart problems ○ Thyroid problems ○ Reduced muscle tone ○ Single palmar crease ○ Small nose ○ Flat nasal bridge
What prenatal tests are in place for DS?
○ Combined ultrasound and blood screening (CUBS) detects 80% cases:
○ Measure nuchal translucency
○ 11-14 week blood tests○ Blood tests at 15-18 weeks: measures levels of AFP and HCG
Draw the screening table:
See one note ‘Right thing to do’ notes in VS notes folder
What is prevalence?
total number of cases of the disease in a population at a given time OR total number of cases in the population divided by the number of individuals in the population
○ (A+C) / (A + B + C + D)
What is sensitivity?
proportion of actual positives that are correctly identified (i.e. the % of sick people that are identified as having the condition)
○ A / (A + C)
What is positive predictive value?
probability that someone with a +ve test actually has a disease
○ A / (A+B)
What is negative predictive value?
probability that someone with a -ve test is actually healthy and disease free
○ D / (C+D)
What are advantages of DS screening?
• Increased choice for parents
• Ability to prepare in advance
Decreased cost to parents if pregnancy terminated
What are disadvantages of DS screening?
- Devaluation of the condition being screened for and it is seen as a ‘bad’ thing
- You are screening for an untreatable condition
- High risk that choice to continue pregnancy will be influenced
- Fears that NHS/insurance may not cover costs of caring for the child if they end up being born and affected with DS
What are the implications associated with terminating a pregnancy?
• Stigma of abortion
• Implication that the condition is “undesirable” or “bad”
• Mentally affects those who have carried a DS child and decided to continue with the pregnancy
• Physical and psychological effects on the mothers health
• Screening with a view to terminate implies that those living with the condition are in some way defective and their lives re reduced in value and quality
○ Depression in those living with the condition
What are the implications of continuing the pregnancy?
- Stigma associated with bearing a “defective” child
- Stigma associated with living with the condition
- Costs of caring for a child and living with the condition
What factors are considered in quality of life decisions?
○ Uncertainty
○ Value judgements
○ Consideration of a persons expectations of life and the reality of what they experience
• They judgements of quality of life are based on the gap between the real and the ideal and the narrower the gap, the greater the quality of life (i.e. the less things you imagine and the more things you realise you have, the better your quality of life)
