The card does not specify if this is a high or low value positive test. The statement on this card is only true if it were referring to a high-value-positive test, therefore misleading.
Example to Clarify:
High-value-positive test (e.g., blood glucose for diabetes):
Lowering the glucose threshold (cutoff point) from 140 mg/dL to 120 mg/dL will increase the sensitivity (more people are caught as diabetic) and NPV (those identified as non-diabetic are more likely truly non-diabetic).
Low-value-positive test (e.g., some hormone levels where lower values indicate disease):
Lowering the cutoff for this type of test would reduce sensitivity, because fewer true positives will be caught, and reduce NPV, because the test would likely miss more people with the disease.
Thus, the modifier "when a higher value indicates a positive test result" is crucial because it specifies the direction of the test and avoids confusion, making sure the interpretation of sensitivity and NPV changes is accurate for tests where higher values indicate disease.
source: see the Anking image in the extra field at the "*note" or First Aid Chapt 26 section 4 for the same image
- Raise cutoff point: will increase things with "p" in the word (p for +, like raising)
- Specificity and PPV increase, and the opposite is the case for sensitivity / NPV
