David L. Watts
Trace Elements, Inc.
A response to the article:
"Assessment of Commercial Laboratories Performing Hair Mineral Analysis"
JAMA 2001 (Jan 3); 285 (1): 67–72
The professional staff of Trace Elements, Inc., (TEI) wish to comment on an article that appeared in the January 3 issue of the Journal of the American Medical Association, “Assessment of Commercial Laboratories Performing Hair Mineral Analysis”. In June of 1999, a split hair sample taken from near the scalp was sent as blind proficiency testing samples to six commercial laboratories in the U.S. The results revealed differences in some of the reference ranges and concentration measurements of 31 elements, thus differences in the interpretations and recommendations provided by the six laboratories. The authors concluded that the entire industry should therefore be characterized as "unreliable".
TEI would like to make the point that a limited study such as this is, in the author's own terms, a "small evaluation of interlaboratory agreement", cannot and should not be represented as a final, rigorous and decisive condemnation of an entire industry. To the contrary, this study simply shows that there is some variation among the labs in measured results, as can be expected. The authors violated scientific standards when they compared test results and reference ranges for laboratories utilizing different methodologies. Another critical flaw with the authors study is that it does not reveal which labs are correct and which labs are wrong, since the authors did not utilize a specific standard or reference laboratory. Furthermore, scientific error is also quite evident in the handling and analysis of the data, which can only guarantee that the authors conclusions will be highly questionable. To be sure, TEI does acknowledge that this limited study does raise some challenging issues that the industry must deal with. First and foremost; identification of laboratories misrepresenting themselves as CLIA certified and operating illegally. Secondly, more improvement should be sought into cooperation between the certified laboratories engaged in hair elemental analysis.
It should be noted that blind proficiency testing, such as used in this study, is the most stringent form of laboratory evaluation, so stringent in fact that it is rarely used in today's clinical laboratories. Modern clinical proficiency testing is overt in that the test specimens are identified as such. This fact coupled with the absence of any gold standard for identifying correct versus incorrect test results seems designed to unfairly target the entire hair analysis industry. Such a standard applied to most clinical tests would result in similar findings. Furthermore, inclusion of a non-certified, unregulated and illegally operating laboratory that represents less than 3% of total hair analysis activity in the U.S. introduced extreme bias and error into the analysis and conclusions based thereon. This one unregulated laboratory was responsible for 12 of the 14 “statistically significant extreme values (P<.05)” cited in the study. The bias of this study is further evident as the authors did not adhere to their own stated laboratory selection protocol. This resulted in a CLIA certified laboratory with significantly higher monthly sample volume not being included in the study in favor of this small non-certified laboratory that reported extreme and dubious measurements.
We at TEI who were included in this limited study, are on record as supporting proficiency testing initiatives, data comparison and clinical case presentations involving hair elemental analysis. We are committed to our profession, to our clients and to our employees as witnessed by our massive investment in staff, operations and in some of the finest modern technology available in the world. TEI is a licensed and certified clinical laboratory that undergoes regular inspections with the Clinical Laboratory Division of the Department of Health and Human Services, HCFA. TEI uses ICP-Mass Spectrometry, the most modern and expensive analytical technique to be applied to routine elemental analysis. TEI performs all testing in a laboratory clean room environment, utilizes the latest microwave digestion apparatus and techniques and has a highly skilled and professional analytical/support staff. Further, each patient result from TEI is based upon an hourly National Institute of Standards and Technology (NIST) traceable standard cure, a rigorous quality control validation for every 24 specimens and is compared to a representative reference range derived from the like analysis of an international collection of normal and “healthy” subjects. TEI also performs routine split samples and participates in a regular test comparison (TC) survey with four other laboratories providing services on an international basis. Needless to say, you can be assured that we stand behind our analytical data.
As stated earlier, the authors suggest that there is excessive variability from one hair analysis laboratory to another. We believe that the matter requires a thorough unbiased investigation involving far more than just one questionable specimen. Calling for the scrutiny of an entire industry based upon a single sample of hair, and involving one small unregulated and illegally operating laboratory is excessive and outrageous by all counts. Not to mention, the orchestrated effort to provide misleading and exaggerated press releases.