There are two principle ways of applying diagnostic test: for confirmation of diagnosis in person with symptoms (confirmatory test) and to detect disease in otherwise healthy individual with no symptoms (screening test). As burden of false positive results is much bigger in screening application of the test, screening tests are subject for more regulated market entry in many European countries.
In the recent article “New diagnostic tests: more harm than good” Hofmann and Gilbert explored potential value of four novel diagnostic tests for clinicians: immunosignature for cancer and infections, breath test for lung cancer, patch vital sign monitoring and biomarkers for Alzheimer’s disease.
For each test researchers raised common concerns for screening tests:
- High rate of false positive results and understated rate of false positive results
- Consequences of results of early testing for person’s insurance and employment
- Downstream cost of further testing and treatment
- Rapid increase in prevalence of disease
- Identification of people with mainly mild conditions
Researches also reference interesting phenomena of potentially misleading feedback to application of diagnostic tests. Thus, at populational level earlier diagnosed people in milder condition would be more satisfied compared with people diagnosed at later stage of disease with more severe condition. At individual level people are generally reassured by [negative] results of testing. So, authors are arguing that the feedback from public and patients can be misleading for policy decision making.
As the measures to counterbalance rapid introduction of novel tests with potential harms researchers suggest:
- Bundling cost of subsequent testing into cost of the test itself
- Rigorous approval process (where exists)
- Shared decision making
- Respect baseline risk – focus on higher risk individuals
- Think downstream – how results of the test would change clinical management of patient?
Read full article here.
Subscribe to our newsletter delivered every second week not to miss important reimbursement information.