Diagnostic Testing can be thought of as occurring in three phases:

1. Pre-analytic phase - everything leading up to the actual testing, including properly filling out a requisition, blood draw, specimen handling, gross examination and tissue fixation

2. Analytic phase - the actual testing itself, which is “flashy” and most people understand

3. Post-analytic phase - results interpretation, report generation, communication with the ordering physician and planning for future testing

If the pre-analytic phase is suboptimal, everything that follows may be unreliable or uninformative.

Colloquially, this is known as “Garbage in, garbage out.”