• chemical pathology
• reflective testing
• add on tests
• post-analytical processing

The processing of chemical pathology requests includes pre-analytical, analytical, and post-analytical phases. At its most basic, the post-analytical process is the reporting and delivery of validated results. One of the ways in which the chemical pathology laboratory provides “added value” over a purely analytical service is at this post-analytical stage—that is, further processing of results related to the request—either before issuing the report, simultaneously, or at a later stage. Indeed, such post-analytical processing is integral to the provision of a quality service, and as such is a requirement for laboratory accreditation in the UK.¹

The simplest form of processing is to compare the result with an appropriate, predefined “action range” (range checking), or to compare changes in sequential results from the same individual to predefined expected ranges of change (delta checking). Historically, this would have been carried out visually by the person authorising paper reports, but now such checks are usually performed by laboratory information systems, which automatically authorise results and generate reports for results that do not fail the checks. Although in many cases the results that fail these tests will be deemed to be acceptable in the clinical circumstances and so no further action would be required, others will require action. This may be as simple …