Tg. Pellar et al., THE FRECKLE PLOT (DAILY TURNAROUND TIME CHART) - A TECHNIQUE FOR TIMELY AND EFFECTIVE QUALITY IMPROVEMENT OF TEST TURNAROUND TIMES, Clinical chemistry, 39(6), 1993, pp. 1054-1059
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.