Hi Holly! The PASS has a fairly high sensitivity and specificity. Sensitivity, however, is the true positive rate – or the likelihood that the score will be positive (above the cut-off) given the person has the condition (future independence with ambulation). Specificity is the true negative rate.
Highly sensitive tests are most useful for ruling IN conditions if the test result is positive. Highly specific tests are most useful for ruling OUT conditions if test results are negative. Therefore, because this patient’s test result was positive (>12.5/36), we are confident that the patient will be independently ambulatory due to the specificity of the PASS.
Sensitivity and specificity are tricky and I need to re-teach myself every time it comes up!
Here are a couple threads from our PCS Advantage forums that discuss sensitivity and specificity a little further that might be helpful. If you search in the forums, you can find other threads where the topic is discussed – and one of us might have found a way to explain it that makes the most sense to you!