A preliminary report is sent when a portion of the samples are completed, but there is still a sample(s) pending. This can happen when a sample is originally overgrown and further steps are taken to try and eliminate background bacteria. This process can take longer than the original processing. Extra time may also be needed if additional work is required to identify a positive sample. Rather than hold completed results until all samples are done, a preliminary report is sent with "Pending" result(s).
A preliminary report will also be sent if multiple tests are requested and one test is complete while the other(s) are not. Most of our tests have varying turnaround times, which means some tests are completed faster than others.