Meaning of result types:
Negative: If a pool result comes back negative, it is safe to assume all members of the pool are negative. Because pool testing is a form of surveillance testing, any participants who are in a pool that tests negative will not be able to receive individualized documentation showing a negative test.
Positive: Should a pool test return a positive result, this does not mean every member of the pool has tested positive. Instead, it indicates Covid-19 was found in at least one sample in the pool.
Invalid: This means either: 1) there was no nucleic acids detected (viral or human); or 2) there was an issue with the sample itself (eg. an upside down swab, more than 10 swabs in a tube, or samples are too old and expired), and the Broad was not able to process it. With the Invalid designation—unlike an inconclusive result—no media was detected or the test was not performed, and it’s as if the person was never tested.
Inconclusive: This means that the test did not detect a clear positive or negative result. An inconclusive result means that the test was run twice, once producing a negative result and once producing a positive result. With an Inconclusive result, the test was performed, but the result is inconclusive and it should be treated as a presumptive positive.
For information of the meaning and implication of each test result type, click here