[Code of Federal Regulations]
[Title 42, Volume 3]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 42CFR493.941]

[Page 1026-1027]
 
                         TITLE 42--PUBLIC HEALTH
 
  CHAPTER IV--CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF 
                  HEALTH AND HUMAN SERVICES (CONTINUED)
 
PART 493_LABORATORY REQUIREMENTS--Table of Contents
 
      Subpart I_Proficiency Testing Programs for Nonwaived Testing
 
Sec. 493.941  Hematology (including routine hematology and coagulation).

    (a) Program content and frequency of challenge. To be approved for 
proficiency testing for hematology, a program must provide a minimum of 
five samples per testing event. There must be at least three testing 
events at approximately equal intervals per year. The annual program 
must provide samples that cover the full range of values that would be 
expected in patient specimens. The samples may be provided through 
mailed shipments or, at HHS' option, may be provided to HHS and or its 
designee for on-site testing.
    (b) Challenges per testing event. The minimum number of challenges 
per testing event a program must provide for each analyte or test 
procedure is five.

                        Analyte or Test Procedure

Cell identification or white blood cell differential
Erythrocyte count
Hematocrit (excluding spun microhematocrit)
Hemoglobin
Leukocyte count
Platelet count
Fibrinogen
Partial thromboplastin time
Prothrombin time

    (1) An approved program for cell identification may vary over time. 
The types of cells that might be included in an approved program over 
time are--

Neutrophilic granulocytes
Eosinophilic granulocytes
Basophilic granulocytes
Lymphocytes
Monocytes
Major red and white blood cell abnormalities
Immature red and white blood cells

    (2) White blood cell differentials should be limited to the 
percentage distribution of cellular elements listed above.
    (c) Evaluation of a laboratory's analyte or test performance. HHS 
approves only those programs that assess the accuracy of a laboratory's 
responses in accordance with paragraphs (c) (1) through (5) of this 
section.
    (1) To determine the accuracy of a laboratory's responses for 
qualitative and quantitative hematology tests or analytes, the program 
must compare the laboratory's response for each analyte with the 
response that reflects agreement of either 80 percent of ten or more 
referee laboratories or 80 percent or more of all participating 
laboratories. The score for a sample in hematology is either the score 
determined under paragraph (c) (2) or (3) of this section.
    (2) For quantitative hematology tests or analytes, the program must 
determine the correct response for each analyte by the distance of the 
response from the target value. After the target value has been 
established for each response, the appropriateness of the response is 
determined using either fixed criteria based on the percentage 
difference from the target value or the number of standard deviations 
(SDs) the response differs from the target value.

                   Criteria for Acceptable Performance

    The criteria for acceptable performance are:

------------------------------------------------------------------------
                                               Criteria for acceptable
              Analyte or test                        performance
------------------------------------------------------------------------
Cell identification.......................  90% or greater consensus on
                                             identification.
White blood cell differential.............  Target 3SD based on the
                                             percentage of different
                                             types of white blood cells
                                             in the samples.
Erythrocyte count.........................  Target 6%.
Hematocrit (Excluding spun hematocrits)...  Target 6%.
Hemoglobin................................  Target 7%.
Leukocyte count...........................  Target 15%.
Platelet count............................  Target 25%.
Fibrinogen................................  Target 20%.
Partial thromboplastin time...............  Target 15%.
Prothrombin time..........................  Target 15%.
------------------------------------------------------------------------

    (3) The criterion for acceptable performance for the qualitative 
hematology test is correct cell identification.
    (4) To determine the analyte testing event score, the number of 
acceptable analyte responses must be averaged using the following 
formula:

[[Page 1027]]




  Number of acceptable responses for the
                  analyte                     x100=Analyte score for the
-------------------------------------------         testing event
Total number of challenges for the analyte
------------------------------------------------------------------------


    (5) To determine the overall testing event score, the number of 
correct responses for all analytes must be averaged using the following 
formula:


  Number of acceptable responses for all
                challenges
-------------------------------------------   x100=Testing event score
      Total number of all challenges
------------------------------------------------------------------------



[57 FR 7151, Feb. 28, 1992, as amended at 58 FR 5229, Jan. 19, 1993; 68 
FR 3702, Jan. 24, 2003]