• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Data Processing and Editing
• Analytic Notes
• Codebook
  • SEQN - Respondent sequence number
  • WTSSCB2Y - Cardiac biomarkers 2 year weights
  • WTSSCB4Y - Cardiac biomarker 4 yr weights 1999-2002
  • SSTNT - Cardiac hs-Troponin T, ng/L
  • SSTNTLC - Cardiac hs-Troponin T comment code
  • SSTNIA - Cardiac hs-Troponin I (Abbott), ng/L
  • SSTNIALC - Cardiac hs-Troponin I (Abbott) comt
  • SSTNIS - Cardiac hs-Troponin I (Siemens), ng/L
  • SSTNISLC - Cardiac hs-Troponin I (Siemens) comt
  • SSTNIO - Cardiac hs-Troponin I (Ortho), ng/L
  • SSTNIOLC - Cardiac hs-Troponin I (Ortho) comt
  • SSPRISTP - Pristine sample comment for SSTROP_A

National Health and Nutrition Examination Survey

1999-2004 Data Documentation, Codebook, and Frequencies

High-sensitivity cardiac troponins (Surplus) (SSTROP_A)

Data File: SSTROP_A.xpt

First Published: September 2022

Last Revised: NA

Component Description

Sera from stored surplus specimens in the NHANES 1999-2004 cycles were tested for high-sensitivity (hs)-troponin T (Roche), hs-troponin I (Abbott), hs-troponin I (Siemens) and hs-troponin I (Ortho). The results for high-sensitivity cardiac troponin in this data release are reported in nanograms per liter (ng/L).   

Eligible Sample

NHANES participants aged 1 year or older who consented to storing their samples for future research and had stored sera samples from 1999-2004.

Description of Laboratory Methodology

This stored specimen study was conducted by the Principal Investigator (PI) Dr. Elizabeth Selvin at the Johns Hopkins Bloomberg School of Public Health. All measurements were performed during 2018-2020 at the University of Maryland School of Medicine, Baltimore, Maryland (Lab Director: Dr. Robert Christenson).

Hs-Troponin T (Roche)

Hs-troponin T, TnT Gen 5 STAT in the USA, was measured using the Roche Cobas e601 using Elecsys reagents. The limit of detection (LoD) for this assay is 3 ng/L.

Total imprecision was expressed as coefficients of variation (CVs). They were 3.1% (26.12–31.28 ng/L) and 2.0% (2004.5–2215.5 ng/L).

Hs-Troponin I (Abbott)

Hs-troponin I (Abbott) was measured using the Abbott ARCHITECT i2000SR. The LoD for this assay is 1.7 ng/L.

CVs: 6.4% (8.12-16.01 ng/L), 4.5% (27.69-55.38 ng/L), 3.5% (169.1-314.1 ng/L), and 6.7% (2758-4444 ng/L).

Hs-Troponin I (Siemens)

Hs-troponin I (Siemens), TNIH assay, was measured using the Siemens Centaur XP. The LoD for this assay is 1.6 ng/L.

CVs: 3.8% (12-28 ng/L), 2.7% (120-280 ng/L), and 2.6% (9000-21000 ng/L).

Hs-Troponin I (Ortho)

Hs-troponin I (Ortho) was measured using the Ortho Vitros 3600. The LoD for this assay is 0.39 ng/L.

CVs: 4.2% (6-16 ng/L) and 2.8% (17511-21403 ng/L).

Data Processing and Editing

Data were received after all analyses were complete. The data were not edited.
Data Access: All data are publicly available. 

Analytic Notes

Refer to the 1999-2000, 2001-2002, and 2003-2004 Laboratory Data Overview for general information on NHANES laboratory data. For information on the stored specimens, refer to the NHANES Biospecimen Program.

Very low concentrations of hs-troponin are associated with greater variability and are not routinely reported for clinical use. However, such values have been unblinded in this dataset for research purposes only.  

For hs-troponin T (Roche) and hs-troponin I (Ortho), low values were initially blinded for each assay. Such values were subsequently unblinded. If unblinding was not possible, the hs-troponin T (Roche) value was imputed as 3 ng/L divided by square root of 2 and the hs-troponin I (Ortho) value was imputed as 0.39 ng/L divided by square root of 2. The hs-troponin I (Siemens) was initially blinded at values below the limit of quantitation (LoQ). If unblinding was not possible, the hs-troponin I (Siemens) value was imputed as 2.5 ng/L divided by square root of 2. For the purposes of this study, the hs-troponin I (Abbott) was not blinded.

The initial lowest reported value before unblinding, limit of the blank (LoB), limit of detection (LoD) and limit of quantitation (LoQ) for hs-troponin T (Roche), hs-troponin I (Abbott), hs-troponin I (Siemens) and hs-troponin I (Ortho) are:

Analyte	Device	Initial lowest reported value before unblinding	LoB	LoD	LoQ
Hs-Troponin T	Roche	3 ng/L	2.5 ng/L	3 ng/L	6 ng/L
Hs-Troponin I	Abbott	-	0.9 ng/L	1.7 ng/L	2.3 ng/L
Hs-Troponin I	Siemens	2.5 ng/L	0.5 ng/L	1.6 ng/L	2.5 ng/L
Hs-Troponin I	Ortho	0.39 ng/L	0.14 ng/L	0.39 ng/L	1.23 ng/L

Two variables are provided for each analyte. The variable prefixed SS (i.e., SSTNT) provides the analytic result for that analyte. The other variable prefixed SS and suffixed with “LC” (ex., SSTNTLC) indicates how the analytic results was obtained: A “0” value means that the result was initially measurable and not blinded. A “1” indicates that the result was initially blinded and was able to be unblinded to provide a measured result. A “2” indicates that the result was initially blinded and was unable to be unblinded, requiring imputation of the result as documented above. For analytes with results that are below the manufacturer-reported LoQ, caution is required for interpretation and values are provided for research purposes only.

The hs-troponin variable names and its corresponding analyte names are: 

Variable Name	Analyte name
SSTNT	Cardiac hs-Troponin T, ng/L
SSTNIA	Cardiac hs-Troponin I (Abbott), ng/L
SSTNIS	Cardiac hs-Troponin I (Siemens), ng/L
SSTNIO	Cardiac hs-Troponin I (Ortho), ng/L

Other variables in this dataset:

An indicator variable (SSPRISTP) is included for whether the analyte was measured in a pristine sample (never previously thawed and re-frozen): 0=non-pristine; 1=pristine.

Variable Name	Description
SSTNTLC	Cardiac hs-Troponin T indicator for values less than blinding threshold value
SSTNIALC	Cardiac hs-Troponin I (Abbott) indicator for greater than/equal or less then LoD
SSTNISLC	Cardiac hs-Troponin I (Siemens) indicator for values less than blinding threshold value
SSTNIOLC	Cardiac hs-Troponin I (Ortho) indicator for values less than blinding threshold value
SSPRISTP	Pristine sample indicator for SSTROP_A

Subsample Weights

Sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data (WTSSCB2Y, WTSSCB4Y). 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. These sample weights are shared with files: “SSCARD_A” and “SSBNP_A”, which were from the same sample of survey participants.

Codebook and Frequencies