NHANES III

Lab Public-Use Data Files Usage Notes

File Location:	LAB
Section:	Hepatitis B surface antibody (SSP)
Date:	August, 2002
Description:	Hepatitis B surface antibody testing was only done on hepatitis B core antibody positives. In 1993, 495 additional samples from participants with a medical occupation who were negative for antibody to hepatitis core antigen were tested to determine mIU/ml of antibody to assess vaccination status. Results of the serum hepatitis B surface antibody can not be used to estimate the vaccination status of the U.S. population since all participants were not tested for this serologic marker.

File Location:	LAB
Section:	Serum Biochemistry Profile - All analytes in Biochemistry Profile
Date:	September, 2002
Description:	Additional note to explain possible storage effect on analytes in biochemistry profile Sera for the Biochemistry Profile was stored at –20o C and then thawed at room temperature. This freeze/thaw cycle has been demonstrated to result in degradation for some analytes in this profile (1-2). Analytes should therefore be used cautiously since degradation could have occurred. Mosley JW, Goodwin RF. Stability of serum-glutamic pyruvic transaminase activity on storage. Tech Bull Regist Med Technol 1965;35:183-187. Young, D.S.,ed., Effects of Preanalytical Variables on Clinical Laboratory Tests, 2nd Edition. AACC Press, Washington DC, 1997.