• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Laboratory Quality Assurance and Monitoring
• Analytic Notes
• Codebook
  • SEQN - Respondent sequence number
  • SSHCVRNA - Hepatitis C RNA
  • SSHCVGEN - Hepatitis C genotype

National Health and Nutrition Examination Survey

2003-2004 Data Documentation, Codebook, and Frequencies

Hepatitis C RNA (HCV-RNA) & HCV Genotype (Surplus) (SSHCVR_C)

Data File: SSHCVR_C.xpt

First Published: July 2012

Last Revised: NA

Component Description

Hepatitis viruses constitute a major public health problem because of the morbidity and mortality associated with the acute and chronic consequences of these infections. New immunization strategies have been developed to eliminate the spread of hepatitis B virus (HBV) and hepatitis A virus (HAV) in the United States. Recommendations have also been developed for the prevention and control of hepatitis C virus (HCV) infection. Because of the high rate of asymptomatic infection with these viruses, information about the prevalence of these diseases is needed to monitor prevention efforts. By testing a nationally representative sample of the U.S. population, NHANES will provide the most reliable estimates of age-specific prevalence needed to evaluate the effectiveness of the strategies to prevent these infections. In addition, NHANES provides the means to better define the epidemiology of other hepatitis viruses. NHANES testing for markers of infection with hepatitis viruses will be used to determine secular trends in infection rates across most age and racial/ethnic groups, and will provide a national picture of the epidemiologic determinants of these infections.

Eligible Sample

The eligible samples are those from the 2003-2004 NHANES with a confirmed positive anti-HCV test result. All participants aged 6 years or older were eligible to be tested for anti-HCV during NHANES 2003-2004.

Description of Laboratory Methodology

Surplus serum samples for 87 specimens that were confirmed anti-HCV positive when tested during NHANES 2003-04 were requested from CASPIR for HCV RNA and genotype testing. Seventy-nine of the requested specimens had vials stored at CASPIR which were shipped to the Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention in April 2011; 76 specimens received had sufficient volume for testing.

Hepatitis C RNA (HCV-RNA)
The COBAS AMPLICOR HCV MONITOR Test, version 2 0 (v2.0) is an in vitro nucleic acid amplification test for the quantitation of Hepatitis C Virus RNA in human serum or plasma on the COBAS AMPLICOR Analyzer.

HCV genotype
The VERSANT ® HCV Genotype 2.0 Assay (LiPA) is a line probe assay designed to identify Hepatitis C virus (HCV) genotypes 1 to 6 in human serum or EDTA plasma samples. Subtype information is available in the majority of cases.

Detailed instructions on specimen collection and processing can be found in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM).

Laboratory Quality Assurance and Monitoring

The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM).

Analytic Notes

NHANES Survey Design:

The analysis of NHANES laboratory data must be conducted with the key survey design and basic demographic variables. The Demographic file contains: Status Variables providing core information on the survey participant including examination status, Recoded Demographic Variables including age, gender, race, etc., and Interview and Examination Sample Weight Variables and Survey Design Variables. The Questionnaire Data Files contain socio-economic data, health indicators, and other related information collected during household interviews. The Phlebotomy Examination file includes auxiliary information on duration of fasting, the time of day of the venipuncture, and the conditions precluding venipuncture. The Demographic, Questionnaire and Phlebotomy Examination files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

The age range and constraints for hepatitis C testing are as follows:

The screening hepatitis C antibody test is performed on all examinees 6 years old or older. Surplus serum samples for those reported for 2003-2004 as confirmed positive for antibody to HCV were tested for HCV RNA. Samples that tested positive or indeterminate for HCV RNA were subsequently tested for HCV genotype.

Exam sample weights should be used for analyses.

All estimates should be checked for statistical reliability due to the small sample size.

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial  for further details on the use of sample weights and other analytic issues.

Codebook and Frequencies