19.07.04 Assessment of tests Flashcards
Why is it important to assess performance of genetic tests
Due to increased availability of tests, important to assess performance for clinical and public health practice
What is ACCE framework
- Analytic validity
- Clinical validity
- Clinical utility
- Ethical, legal and social implications
What is analytical validity
How accurately and reliably the test measures the genotype of interest. Based on data from labs: method, validation process, sensitivity, specificity, reliability and reproducibility.
What is clinical validity
How consistently and accurately the test detects or predicts the intermediate of final outcomes of interest.
What is a clinical positive predictive value
Probability of having/ developing the disease with a positive test results. Penetrance?
What is a clinical negative predictive value
Probability of NOT having/not developing the disease with a negative test results. Locus/allelic heterogeneity.
What is clinical sensitivity
Probability of a positive result when the condition is known to be present. Will be reduced if there is locus/allelic heterogeneity.
What is clinical utility
How likely the test is to significantly improve patient outcomes
How can genetic testing improve patient outcomes
- Aids diagnosis. Avoids invasive/expensive tests. e.g.g muscle biopsy in DMD.
- Could lead to altered treatment: F508del or G551D in CF and Ivacaftor drug.
- Aids prognosis and managements. ATM mutation carriers avoid X-rays.
- Presymptomatic testing in other family members. Could lead to early disease detection (hereditary cancer predispositions)
- Genetic risk assessment: reduce the need for clinical tests in family members that have tested negative for variant.
Who developed the ACCE framework
CDC’s (Centre of disease control and prevention, in the USA) Office of Public health genomics (OPHG)
Purpose of framework
It is a process to allow policy makers to see data about DNA testing, to enable decision making. Helps to identify gaps in knowledge that will help define future research agendas.
What is UKGTN
UK Genetic testing network. An advisory organisation that provided commissioning support to NHS and Department of health. No longer active (since 2018).
Will be continued after restructuring of genetic services in NHS England.
Purpose of UKGTN
To ensure equity of access to genetic testing. Acts as a coordinated body that identifies lab services (directory of all tests offered), has a criteria for labs to be a member (accredited), evaluates new services (gene dossiers)
What is UKGTN CSAG
Clinical and Scientific advisory group. Acts in a commisionary advisory capacity to influence national policy
What does the GTEWG do?
Genetic test evaluation working group. Evaluates gene dossiers and passes successful ones on to CSAG for ratification and then to commissioners to fund tests.