Post-analytical 'error' rates in point-of-care testing: use of a quality assurance programme

Laboratory tests are subject to error, pre-analytical, analytical and post-analytical. Post-analytical error includes misinterpretation of results. Point-of-care testing (POCT) can be subject to the same errors This study utilized an external quality assurance programme for capillary blood glucose and 'dipstick' urinalysis to investigate post-analytical errors of result interpretation by various grades of nurse performing POCT. When the results simulated a hypoglycaemic patient, 84.1% of nurses interpreted the results correctly. In the case of diabetes mellitus, 95.7% of nurses interpreted the results correctly. Whereas in the simulation of a case where the capillary blood glucose was falsely raised due to puncture site contamination only 5.4% of nurses interpreted the POCT results correctly. As the seniority of the nurse made little or no difference to the interpretation given, this study demonstrated the need for improved training within the Taunton and Somerset NHS Trust Hospital.