Table of Contents

Locator Record

Title: Prostate Specific Antigen (PSA) Exclusion Questions and Lab Results (L11PSA_C )
Contact Number: 1-866-441-NCHS
Years of Content: 2003 - 2004
First Published: February, 2006
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:Prostate specific antigen (PSA)
Record Source: NHANES 2003 - 2004
Survey Methodology: NHANES 2003 - 2004 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

Prostate cancer is the most common non-skin malignancy among men, with approximately 180,000 new cases diagnosed and 37,000 deaths in 1999. The total and free prostate-specific antigen (PSA) tests have been recognized as tumor markers for the screening, diagnosis, and management of prostate cancer.

Total and free PSAs were measured among men age 40 years and older. PSA exclusion questions (KIQ115, KIQ185, KIQ190, KIQ195, KIQ201, KIQ241, KIQ281, KIQ301, and KIQ311) were asked during the physician’s examination. PSA immunoassay was performed on blood specimens using the Hybritech tests (Beckman Coulter, Fullerton, CA).

Eligible Sample

Male participants aged 40 years and older were tested for PSA. Those who reported having any of the following conditions were not eligible for PSA testing:

Description of Laboratory Methodology

Free PSA

The Access Hybritech free PSA assay is a two-site immuno-enzymatic "sandwich" assay. A sample was added to a reaction vessel with mouse monoclonal anti-free PSA alkaline phosphatase conjugate, and paramagnetic particles coated with a second mouse monoclonal anti-free PSA antibody. The free PSA in the sample bound to the immobilized monoclonal anti-free PSA on the solid phase, while at the same time, the monoclonal anti-PSA conjugate reacted with a different antigenic site on the sample free PSA. Separation in a magnetic field and washing removes material not bound to the solid phase. A chemiluminescent substrate, Lumi-Phos 530 was added to the reaction vessel, and light generated by the reaction was measured with a luminometer. The light production was proportional to the concentration of free PSA in the sample. The amount of analyte in the sample was determined by means of a stored, multi-point calibration curve.

Total PSA

Total PSA values were obtained using the Hybritech PSA method on the Beckman Access. A second sample was added to a reaction vessel with mouse monoclonal anti-PSA alkaline phosphatase conjugate and paramagnetic particles coated with a second mouse monoclonal anti-PSA antibody. The PSA in the sample bound to the immobilized monoclonal anti-PSA on the solid phase while, at the same time, the monoclonal anti-PSA conjugate reacted with a different antigenic site on the sample PSA. The light production was proportional to the concentration of PSA in the sample.

PSA ratio

This ratio was calculated by dividing the free PSA by the total PSA:

LBDP3 = round ((LBXP2/LBXP1)*100)

There were no changes to the equipment, lab method, or lab site from the previous 2 years.

A detailed description of the laboratory method used can be found on the NHANES website.

Data Processing and Editing

Blood specimens are processed, stored and shipped to University of Washington, Seattle, WA. Detailed specimen collection and processing instructions are discussed in the NHANES LPM. Read the LABDOC file for detailed data processing and editing protocols. The analytical methods are described in the Analytic methodology section.

Because of a potential disclosure risk, the KID221 question was recoded by creating an “85 or greater” response category. Any participant reported as being diagnosed with prostate cancer at age 85 years or older was recoded to an “85 or greater” years response.

One derived variable was created in this data file. This PSA ratio was calculated by dividing the free PSA by the total PSA:

LBDP3 = round ((LBXP2/LBXP1)*100).

Detailed instructions on specimen collection and processing can be found on the NHANES website.

Laboratory Quality Assurance and Monitoring

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

A detailed description of the quality assurance and quality control procedures can be found on the NHANES website.

Analytic Notes

The analysis of NHANES 2003–2004 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2003–2004 Questionnaire Data Files contain demographic data, health indicators, and other related information collected during household interview and MEC examination. They also contain sample weights for these age groups. The phlebotomy file includes auxiliary information, such as the conditions precluding venipuncture. The household questionnaire and phlebotomy files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

Data on health conditions that would make a sample person ineligible for PSA testing are missing for some people with non-missing PSA lab data. This omission exists mainly because some sample persons did not attend the physician’s examination component of the MEC examination where such data were collected. It is advisable to exclude these observations for PSA analyses.

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Males only 40 YEARS - 150 YEARS

KIQ110 - Willing to have blood tested for PSA

Variable Name:
KIQ110
SAS Label:
Willing to have blood tested for PSA
English Text:
Are you willing to have your blood tested for PSA?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 1381 1381
2 No 33 1414 End of Section
7 Refused 0 1414
9 Don't know 2 1416
. Missing 91 1507

KIQ115 - Infection or inflammation of prostate

Variable Name:
KIQ115
SAS Label:
Infection or inflammation of prostate
English Text:
{Do you/does SP} have an infection or inflammation of the prostate gland at the present time?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 14 14
2 No 1353 1367
7 Refused 0 1367
9 Don't know 13 1380
. Missing 127 1507

KIQ185 - Rectal exam in the last 7 days

Variable Name:
KIQ185
SAS Label:
Rectal exam in the last 7 days
English Text:
{Have you/Has SP} had a rectal exam in the last 7 days?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 21 21
2 No 1359 1380
7 Refused 0 1380
9 Don't know 0 1380
. Missing 127 1507

KIQ190 - Prostate biopsy in the last 4 weeks

Variable Name:
KIQ190
SAS Label:
Prostate biopsy in the last 4 weeks
English Text:
{Have you/Has SP} had a prostate biopsy in the last 4 weeks?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 2 2
2 No 1376 1378
7 Refused 0 1378
9 Don't know 1 1379
. Missing 128 1507

KIQ195 - Cystoscopy in the last 4 weeks

Variable Name:
KIQ195
SAS Label:
Cystoscopy in the last 4 weeks
English Text:
{Have you/Has SP} had a cystoscopy in the last 4 weeks? (Cystoscopy is an internal examination of the prostate and bladder using a flexible tube-like instrument with a lens inserted through the penis.)
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 3 3
2 No 1376 1379
7 Refused 0 1379
9 Don't know 0 1379
. Missing 128 1507

KIQ201 - Diagnosed with prostate cancer

Variable Name:
KIQ201
SAS Label:
Diagnosed with prostate cancer
English Text:
{Have you/Has SP} ever been told by a doctor or health professional that {you/he} had prostate cancer?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 57 57
2 No 1322 1379 End of Section
7 Refused 0 1379 End of Section
9 Don't know 0 1379 End of Section
. Missing 128 1507

KID221 - Age at diagnosis of prostate cancer

Variable Name:
KID221
SAS Label:
Age at diagnosis of prostate cancer
English Text:
How old {were you/was SP} when {you were/he was} first told that {you/he} had prostate cancer?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
Age at diagnosis of prostate cancer Value was recorded 56 56
777 Refused 0 56
999 Don't know 0 56
< blank > Missing 1451 1507

KIQ241 - Ever had prostate surgery

Variable Name:
KIQ241
SAS Label:
Ever had prostate surgery
English Text:
{Have you/Has SP} ever had surgery on {your/his} prostate?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 33 33
2 No 24 57 KIQ301
7 Refused 0 57 KIQ301
9 Don't know 0 57 KIQ301
. Missing 1450 1507

KIQ281 - Was surgery for prostate cancer?

Variable Name:
KIQ281
SAS Label:
Was surgery for prostate cancer?
English Text:
Was the surgery for cancer of the prostate gland?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 30 30
2 No 3 33
7 Refused 0 33
9 Don't know 0 33
. Missing 1474 1507

KIQ301 - Radiation treatment for prostate cancer

Variable Name:
KIQ301
SAS Label:
Radiation treatment for prostate cancer
English Text:
{Have you/Has SP} ever had radiation treatments for prostate cancer?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 24 24
2 No 33 57
7 Refused 0 57
9 Don't know 0 57
. Missing 1450 1507

KIQ311 - Taken medicines for prostate cancer

Variable Name:
KIQ311
SAS Label:
Taken medicines for prostate cancer
English Text:
{Have you/Has SP} ever taken prescribed medicines for prostate cancer?
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Yes 19 19
2 No 37 56
7 Refused 0 56
9 Don't know 1 57
. Missing 1450 1507

LBXP1 - PSA. total (ng/mL)

Variable Name:
LBXP1
SAS Label:
PSA. total (ng/mL)
English Text:
Prostate specific antigen, total (ng/mL)
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.2 to 72.7 Range of Values 1301 1301
0.1 Below Limit of Detection 20 1321
. Missing 186 1507

LBXP2 - PSA, free (ng/mL)

Variable Name:
LBXP2
SAS Label:
PSA, free (ng/mL)
English Text:
Prostate specific antigen (PSA), free (ng/mL)
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.05 to 5.27 Range of Values 1299 1299
0.04 Below Limit of Detection 22 1321
. Missing 186 1507

LBDP3 - Prostate specific antigen ratio (%)

Variable Name:
LBDP3
SAS Label:
Prostate specific antigen ratio (%)
English Text:
Prostate specific antigen ratio (%)
Target:
Males only 40 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4 to 100 Range of Values 1321 1321
. Missing 186 1507