Protocol - Complete Blood Count (CBC)

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The Complete Blood Count (CBC) protocol is a standard blood panel from the National Health and Nutrition Examination Survey (NHANES). 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.

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 manufacturers instructions and according to the laboratorys 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.

The Sickle Cell Disease Curative Therapy Working Group recommends that complete blood count be determined in hematopoietic cell transplant patients at the following timepoints (at minimum): one time point pre-transplant (baseline) and 100 days, six months, and annually post-transplant.




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
Major equipment No
Specialized training No
Specialized requirements for biospecimen collection No
Average time of greater than 15 minutes in an unaffected individual No
Mode of Administration



Toddler, Child, Adolescent, Adult


All ages.

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.



caDSR Form PhenX PX220501 - Complete Blood Count Cbc 6889016 caDSR Form
Derived Variables


Process and Review

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

Protocol Name from Source

National Health and Nutrition Examination Survey (NHANES), Laboratory procedures Manual, 2010


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 Name Variable IDVariable DescriptiondbGaP Mapping
PX220501_CompleteBloodCount _Age
PX220501030000 Age Variable Mapping
PX220501_CompleteBloodCount _Blood_Draw_Results
PX220501040000 Record the results of the blood draw. N/A
PX220501_CompleteBloodCount _Blood_Draw_Tube_Deviation
PX220501050000 Record reasons for a tube not being drawn more
according to the protocol. show less
PX220501_CompleteBloodCount _Chemotherapy_4weeks
PX220501020000 Have you received cancer chemotherapy in the more
past four weeks or do you anticipate such therapy in the next four weeks? show less
PX220501_CompleteBloodCount _hemophilia
PX220501010000 Do you have hemophilia? Variable Mapping
PX220501_CompleteBloodCount _Venipuncture_Comments
PX220501060000 Record any comments about the venipuncture. Variable Mapping
PX220501120000 Basophils Variable Mapping
PX220501170000 Basophils number Variable Mapping
PX220501110000 Eosinophils Variable Mapping
PX220501160000 Eosinophils number Variable Mapping
PX220501200000 Hematocrit Variable Mapping
PX220501190000 Hemoglobin Variable Mapping
PX220501080000 Lymphocyte Variable Mapping
PX220501130000 Lymphocyte number Variable Mapping
PX220501230000 MCHC Variable Mapping
PX220501220000 Mean cell hemoglobin Variable Mapping
PX220501210000 Mean cell volume Variable Mapping
PX220501260000 Mean platelet volume Variable Mapping
PX220501090000 Monocyte Variable Mapping
PX220501140000 Monocyte number Variable Mapping
PX220501250000 Platelet count Variable Mapping
PX220501180000 Red cell count Variable Mapping
PX220501240000 Red cell distribution width Variable Mapping
PX220501100000 Segmented neutrophils Variable Mapping
PX220501150000 Segmented neutrophils number Variable Mapping
PX220501070000 White blood cell count Variable Mapping
Rare Genetic Conditions
Measure Name

Complete Blood Count (CBC)

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.


Complete blood count, CBC, red blood cells, white blood cells, hemoglobin, hematocrit, eosinophils, basophils, platelets, National Health and Nutrition Examination Survey, NHANES, gerontology, aging, geriatrics, sickle cell disease, SCD

Measure Protocols
Protocol ID Protocol Name
220501 Complete Blood Count (CBC)

There are no publications listed for this protocol.