Complete Blood Count
Date of SC final approval
About the Measure
Domain:
Rare Genetic Conditions
Measure:
Complete Blood Count (CBC)
Definition:
A Complete Blood Count (CBC) is a standardized test to assess components of the
blood (e.g., red blood cells, white blood cells, hematocrit, hemoglobin, platelets).
Complete Blood Count (CBC) tests are performed to determine the overall health of an
individual and may help identify underlying conditions. CBC test results may identify a
broad range of common and rare diseases.
Purpose:
About the Protocol
Description of
Protocol:
Selection
Rationale:
Specific
Instructions:
The Complete Blood Count (CBC) protocol is a standard blood panel from the
National Health and Nutrition Examination Survey (NHANES) and performed on
participants aged 1 and older. Blood is collected from participants via standard
venipuncture in a 3 or 4 ml K3 EDTA tube. The ambient blood sample is placed into a
hematological analyzer for CBC and differential analyses. The blood should be tested
as soon as possible after venipuncture and no later than 24 hours.
A complete count is done by a machine and the numbers and indices may suggest a
range of underlying diagnoses. Examination of a blood smear or additional testing is
likely to be necessary to confirm a specific diagnosis.
Although this protocol specifies using the Coulter® HMX Hematology Analyzer, other
automated hematology analyzers may be used. The Complete Blood Count (CBC)
tests can be performed by any Clinical Laboratory Improvement Amendments (CLIA)
certified laboratory that follows Clinical & Laboratory Standards Institute guidelines for
quality assurance and quality control. Commercial laboratories perform CBC tests
routinely, and they are inexpensive.
The Rare Genetic Conditions WG recommends that the investigator record whether
the blood was drawn and whether the full amount was obtained. Although this protocol
specifies filling a 3- or 4- mL K3 EDTA tube, investigators may only need to draw
enough blood to complete the tests being ordered.
Protocol Text:
Exclusion Criteria
Persons will be excluded from this component if they:
• Report that they have hemophilia; or
• Report that they have received cancer chemotherapy in the last 4 weeks
SP = Sample Person.
1. Do you have hemophilia?
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Complete Blood Count
Date of SC final approval
1[]
2[]
7[]
9[]
Yes
No
Refused
Don’t Know
If the SP answers, "Yes," the SP is excluded from the blood draw.
If SP answer "No" or "Don’t Know," blood is drawn from the SP.
2. Have you received cancer chemotherapy in the past four weeks or do you
anticipate such therapy in the next four weeks?
1[]
2[]
7[]
9[]
Yes
No
Refused
Don’t Know
If the SP answers, "Yes," the SP is excluded from the blood draw.
If SP answer "No" or "Don’t Know," blood is drawn from the SP.
Venipuncture Procedures
Editor’s Note: Please review chapter 4 of the Laboratory Procedures Manual from the
2009–2010 National Health and Nutrition Examination Survey for a full description of
Phlebotomy procedures.
Venipuncture should generally be performed using the median cubital, cephalic, or
basilic veins in the left arm unless this arm is unsuitable. If the veins in the left arm are
unsuitable, look for suitable veins on the right arm. If the veins in the antecubital
space on both arms are not suitable, then look for veins in the forearm or dorsal side
of the hand on the left arm/hand and then the right arm/hand.
Fill a 3 or 4 ml K3 EDTA tube with blood.
Recording the Results of the Venipuncture Procedure
Immediately after completing the venipuncture, record the results of the blood draw,
the reasons for a tube not being drawn according to the protocol, and any comments
about the venipuncture.
Perform CBC Analyses
There are a number of different assays and Clinical Laboratory Improvement
Amendments (CLIA) certified instruments that are appropriate to perform the CBC
analyses. Once an assay is chosen for a particular study, the Working Group
recommends that no changes in the protocol be made over the course of the study.
To aid comparability, the Working Group recommends that the investigator record the
make and manufacturer of equipment used and the repeatability and coefficients of
variation for the assay.
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Complete Blood Count
Date of SC final approval
Note: a full description of the NHANES procedure is found in the 2009–2010 NHANES
Lab Procedures Manual. If the Coulter® HMX Hematology Analyzer is utilized, it
should be calibrated per the manufacturer’s recommendations. NHANES performs the
test in duplicate, but this may not be necessary.
The following parameters and units are measured in the CBC panel test.
White blood cell count (1,000 cells/uL)
Lymphocyte (%)
Monocyte (%)
Segmented neutrophils (%)
Eosinophils (%)
Basophils (%)
Lymphocyte number (1,000 cells/uL)
Monocyte number (1,000 cells/uL)
Segmented neutrophils number (1,000 cells/uL)
Eosinophils number (1,000 cells/uL)
Basophils number (1,000 cells/uL)
Red cell count (million cells/uL)
Hemoglobin (g/dL)
Hematocrit (%)
Mean cell volume (fL)
Mean cell hemoglobin (pg)
MCHC (g/dL)
Red cell distribution width (%)
Platelet count (1,000 cells/uL)
Mean platelet volume (fL)
Interpretation of the CBC Results
Participant:
The 2009–2010 NHANES Laboratory Procedures Manual includes several tables of
normal ranges for the CBC tests, see Chapter 7, pg 125.
Age 1 and older
Source:
Centers for Disease Control and Prevention (CDC), National Center for Health
Statistics (NCHS). (2010). Complete Blood Count. In Laboratory procedures manual
(pp. 7-3–7-130). Hyattsville, MD: U.S. Department of Health and Human Services,
Centers for Disease Control and Prevention.
Language of
Source:
English
Personnel and
Training Required:
Phlebotomist
Laboratory that can perform Complete Blood Count (CBC) test
Equipment Needs:
Phlebotomy supplies
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Complete Blood Count
Date of SC final approval
Protocol Type:
Bioassay
Requirements:
Requirements Category
Common Data
Elements:
General
References:
Required (Yes/No):
Major equipment
No
Specialized training
No
Specialized requirements for biospecimen
collection
Average time of greater than 15 minutes in an
unaffected individual
No
No
Cheng, C. K., Chan, J., Cembrowski, G. S., & van Assendelft, O. W. (2004). Complete
blood count reference interval diagrams derived from NHANES III: Stratification by
age, sex, and race. Laboratory Hematology, 10(1), 42–53.
Lim, E. M., Cembrowski, G., Cembrowski, M., & Clarke, G. (2010). Race-specific
WBC and neutrophil count reference intervals. International Journal of Laboratory
Hematology, 32(6 Pt. 2), 590–597.
Additional Information About the Measure
Essential Data:
Current Age
Related PhenX
Measures:
Derived Variables:
Lipid Profile
Keywords/Related
Concepts:
Complete blood count, CBC, red blood cells, white blood cells, hemoglobin,
hematocrit, eosinophils, basophils, platelets, National Health and Nutrition
Examination Survey, NHANES
None
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