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Basis for accuracy?
Hi all,
This is more of a conceptual question than anything personal. When we read about a test having 99% accuracy (or to put a finer point on it, 99% specificity), what is going on? In other words, what is the source of error?
Is it just the nature of the given test? If this is the case, would 2 consecutive tests (all other things being equal) bring the specificity to 99.99%?
Or is it the nature of the infection being tested? If this is the case, you wouldn't expect consecutive tests to improve the odds.
This is more of a conceptual question than anything personal. When we read about a test having 99% accuracy (or to put a finer point on it, 99% specificity), what is going on? In other words, what is the source of error?
Is it just the nature of the given test? If this is the case, would 2 consecutive tests (all other things being equal) bring the specificity to 99.99%?
Or is it the nature of the infection being tested? If this is the case, you wouldn't expect consecutive tests to improve the odds.
The reason it's 99% and not 100% is that there is always room for error and nothing is ever truly 100% in science. And also, as far as false negatives are concerned, there is a window period where infection won't be picked up yet the person is HIV positive.
Specificity refers to positive results being true positives.
Sensitivity refers to negative results being true negatives.
Sensitivity refers to negative results being true negatives.
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