THE FRECKLE PLOT (DAILY TURNAROUND TIME CHART) - A TECHNIQUE FOR TIMELY AND EFFECTIVE QUALITY IMPROVEMENT OF TEST TURNAROUND TIMES

Test turnaround times are often monitored on a monthly basis. However, such an interval usually means that not all causes for delay in test reporting can be unequivocally identified for institution of remedial action. We have devised a daily chart-the freckle plot-that graphicall y displays the test turnaround times by laboratory receipt time. Diffe rent symbols are used to designate specimens reported within the test' s turnaround time limit, those within 10 min beyond that limit, and th ose well outside the limit. These categories are adjustable to suit di fferent limits of stringency. Freckle plots are produced on a daily ba sis and can be used to track down causes for test delays. Using the 1- h turnaround time ''stat'' potassium test as a model, we found 16 caus es for test delay, of which 9 were potentially remediable. By applying these remedies, we were able to increase test compliance, in the day shift, from 91.5% (95% confidence interval 88.8-93.7%) to 97.6% (95% c onfidence interval 96.4-98.55%), which is significant at P < 10(-7)). This daily plot is a useful quality assurance tool, supplementing the more conventional tests used to ensure laboratory quality improvement.