WSLH Toxicology: Blood Lead Proficiency Testing FAQs

Frequently Asked Questions

Q. When should I expect to receive samples?

Q. What if I can't report by the due date?

Q. What if I report results after the due date?

Q. My LeadCare instrument reports results to a decimal place, what do I report?

Q. When are the < and > boxes on the blood lead report form used?

Q. Do I have to re-enroll every year?

Q. Are supplemental/remedial events available?

Q. Do you offer other proficiency testing programs?

Q. How should I store my PT samples prior to analysis?

Q. When should I expect to receive samples?
A. Proficiency samples are shipped in January, March, May, July, September, and November on the second Monday of each month, with result reports due two weeks later. If you have not received samples by the third Monday of the month, please contact us at 608-224-6252 or toxpt@mail.slh.wisc.edu to request replacements. Also, the sample shipping date for the next event is noted on the back of the report form of the current event.

Q. What if I can't report by the due date?
A. Contact us at 608-224-6252 on or before the due date to request an extension of the due date or to be excused for that event.

Q. What if I report results after the due date?

Regulatory (5 specimen) events:
Late results receive a score of zero. Exceptions are not made unless we have been contacted on or before the due date. It is beneficial to report late results even though they receive a score of zero, as the event report lists your quantitative results and shows the quality of your work. Reports received after the event has been graded are not evaluated.

Non-regulatory (3 specimen) events:
Results are not scored as late. You will receive a report evaluating your performance or, if the report is received after the event has been graded, a report stating no results were received.

Q. My LeadCare instrument reports results to a decimal place, what do I report?
A. It is program policy for results to be reported to a whole number, so decimal results should be rounded to the nearest whole number. If you fail to round your results, they may be scored incorrectly. The rounding policy used in our lab is: 0.1-0.4 round down; 0.5 round to the nearest even whole number; 0.6-0.9 round up. Note that the report form does not have a box for decimal results. Do not attempt to put multiple numerals in a box.

Q. When are the < and > boxes on the blood lead report form used?
A. The less than (<) and greater than (>) boxes are used for results outside the quantitative range of your method. The quantitative range is the range in which you feel confident reporting a numerical result. For example, the LeadCare instrument provides a quantitative result up to 65 µg/dL; beyond 65 µg/dL the display reads HI. The upper limit of the quantitative range for the LeadCare instrument is 65 µg/dL; readings of HI should be reported as >65 µg/dL. Most labs have a similar limit for very low results i.e., a result of 1 µg/dL may be reported as <2 µg/dL. The LeadCare II instrument displays Low when the result is less than 3.3 µg/dL and High when the result is greater than 65.0 µg/dL.  Readings of Low should be reported as < 3 µg/dL and readings of High should be reported as > 65 µg/dL.  Do not use < or > to indicate that a result was rounded up or down.

Q. Do I have to re-enroll every year?
A. Participants enrolled in both the bi-monthly and regulatory blood lead program are automatically re-enrolled for the next year. Participants enrolled in other WSLH PT programs and those enrolled in the regulatory blood lead program without the bi-monthly program must re-enroll each year.

Q. Are supplemental/remedial events available?
A. Yes, participants seeking remedial PT must submit a written request and include the name and mailing address of the regulatory agency to which results should be sent. Participants are limited to two remedial events within a 12-month period.

Q. Do you offer other proficiency testing programs?
A. Yes, the WSLH offers a variety of proficiency testing programs.  Go to http://www.wslhpt.org for more information.

Q. How should I store my PT samples prior to analysis?
A. The speciments should generally be stored the same way that your patient specimans are stored. Typically, this will mean under refrigerated or frozen temperatures. Users of hand-held lead analyzers (LeadCare, LeadCare II) should test the specimens on the day of receipt, or dilute into the reagent and store under refrigeration to be consistent with procedures recommended by the manufacturer. Filter paper blood lead specimens are typically stored at room temperature.