Protocol - Complete Blood Count (CBC)

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This section will be completed when reviewed by an Expert Review Panel.


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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.


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?

1 [ ] Yes

2 [ ] No

7 [ ] Refused

9 [ ] 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 [ ] Yes

2 [ ] No

7 [ ] Refused

9 [ ] 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

Note: a full description of this 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 (1000 cells/uL)

Lymphocyte (%)

Monocyte (%)

Segmented neutrophils (%)

Eosinophils (%)

Basophils (%)

Lymphocyte number (1000 cells/uL)

Monocyte number (1000 cells/uL)

Segmented neutrophils number (1000 cells/uL)

Eosinophils number (1000 cells/uL)

Basophils number (1000 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 (1000 cells/uL)

Mean platelet volume (fL)

Interpretation of the CBC Results

The 2009-2010 NHANES Laboratory Procedures Manual includes several tables of normal ranges for the CBC tests, see Chapter 7, pg 125.

Personnel and Training Required


Laboratory that can perform Complete Blood Count (CBC) test

Equipment Needs

Phlebotomy supplies


Requirement CategoryRequired
Average time of greater than 15 minutes in an unaffected individualNo
Major equipmentNo
Specialized requirements for biospecimen collectionNo
Specialized trainingNo

Mode of Administration


Life Stage:

Toddler, Child, Adolescent, Adult

Specific Instructions:

Blood should be drawn directly into an EDTA anticoagulated tube. Venipuncture is preferred rather than capillary blood draw although arterial blood may be used. The tube should be filled to the maximum volume stated.

Although this assay specifies the Coulter® HMX Hematology Analyzer, there are a number of different assays and instruments that are appropriate to perform the CBC analyses. Commercial laboratories perform CBC tests routinely, and they are inexpensive. Blood should be analyzed according to the instrument manufacturer's instructions and according to the laboratory's standard operating procedure and interpreted in the context of age specific normal values. 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.

Investigators who want to include participants that have hemophilia or have received cancer chemotherapy in the last 4 weeks will need to implement special venipuncture procedures.

Research Domain Information

Release Date:

July 30, 2015


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.

Selection Rationale

A complete blood 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.




Common Data Elements (CDE)Complete Blood Cell Count Laboratory Test Result Value4921936CDE Browser

Process and Review

This section will be completed when reviewed by an Expert Review Panel.


Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS). (2010). Complete Blood Count. In Laboratory procedures manual (pp. 7-3 through 7-130). Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention.

General References

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.

Protocol ID:



Export Variables
Variable NameVariable IDVariable DescriptionVersiondbGaP Mapping
PX220501_CompleteBloodCount _hemophiliaPX220501010000Do you have hemophilia?4N/A
PX220501_CompleteBloodCount _Chemotherapy_4weeksPX220501020000Have you received cancer chemotherapy in the past four weeks or do you anticipate such therapy in the next four weeks?4N/A
PX220501_CompleteBloodCount _AgePX220501030000Age4N/A
PX220501_CompleteBloodCount _Blood_Draw_ResultsPX220501040000Record the results of the blood draw.4N/A
PX220501_CompleteBloodCount _Blood_Draw_Tube_DeviationPX220501050000Record reasons for a tube not being drawn according to the protocol.4N/A
PX220501_CompleteBloodCount _Venipuncture_CommentsPX220501060000Record any comments about the venipuncture.4N/A
PX220501_CompleteBloodCount_White_Blood_Cell_CountPX220501070000White blood cell count4N/A
PX220501_CompleteBloodCount_Segmented_NeutrophilsPX220501100000Segmented neutrophils4N/A
PX220501_CompleteBloodCount_Lymphocyte_NumberPX220501130000Lymphocyte number4N/A
PX220501_CompleteBloodCount_Monocyte_NumberPX220501140000Monocyte number4N/A
PX220501_CompleteBloodCount_Segmented_Neutrophils_NumberPX220501150000Segmented neutrophils number4N/A
PX220501_CompleteBloodCount_Eosinophils_NumberPX220501160000Eosinophils number4N/A
PX220501_CompleteBloodCount_Basophils_NumberPX220501170000Basophils number4N/A
PX220501_CompleteBloodCount_Red_Cell_CountPX220501180000Red cell count4N/A
PX220501_CompleteBloodCount_Mean_Cell_VolumePX220501210000Mean cell volume4N/A
PX220501_CompleteBloodCount_Mean_Cell_HemoglobinPX220501220000Mean cell hemoglobin4N/A
PX220501_CompleteBloodCount_Red_Cell_Distribution_WidthPX220501240000Red cell distribution width4N/A
PX220501_CompleteBloodCount_Platelet_CountPX220501250000Platelet count4N/A
PX220501_CompleteBloodCount_Mean_Platelet_VolumePX220501260000Mean platelet volume4N/A