Study Participants | National Institute of Environmental Health Sciences
Source: https://www.niehs.nih.gov/research/atniehs/labs/crb/studies/pegs/about/participants
Archived: 2026-04-23 17:12
Study Participants | National Institute of Environmental Health Sciences
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PEGS: Personalized Environment and Genes Study
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PEGS was initially established as the Environmental Polymorphisms Registry, which was a cross-sectional cohort with participants selected by convenience sampling. In 2002, the Environmental Polymorphisms Pilot Study (EPPS) was established to assess willingness to participate in such a cohort and to determine the efforts that would be needed for recruitment. The goal of EPPS was to enroll 500 subjects through outpatient medical clinics in the UNC Healthcare System. Based on the favorable response rate, enrollment for EPR/PEGS began in 2005, with the goal of recruiting 20,000 individuals living in the greater Research Triangle Park (RTP) region in North Carolina who reflect the overall demographics of the area in terms of age, sex, race and ethnicity.
PEGS participants were recruited from outpatient clinics and hospitals in the region as well as from the general population at over 200 unique sites, including clinical centers, hospitals, corporate offices, community health fairs, career fairs, colleges and universities, charity walks and races, senior centers, sporting events, social clubs, religious institutions, military bases, festivals and other community events. The PEGS cohort comprises 19,445 participants, and enrollment is ongoing at the National Institute of Environmental Health (NIEHS)
Clinical Research Unit
(CRU) in North Carolina, the National Institutes of Health (NIH)
Clinical Center
in Maryland, the
PEGS enrollment website
and
Clinicaltrials.gov
. Except for the NIH Clinical Center in Maryland, all recruitment sites are in North Carolina.
Contact is maintained with PEGS participants through email, flyers and phone calls to update their personal information, reduce attrition and maximize response rates for follow-up studies. Current contact information is maintained on as many subjects as possible using a combination of annual mailings,
newsletters
, emails and telephone calls. Subjects agree to be contacted for follow-up studies for up to 25 years after enrollment.
Participant Demographics
Demographic Variable
Value
Sex (N, %)
Female
12,120 (62.3)
Male
7,298 (37.5)
Race (N, %)
White
12,279 (63.1)
Black or African American
5,361 (27.6)
Other
868 (4.5)
Ethnicity (N, %)
Non-hispanic / Non-latino
17,750 (91.3)
Hispanic Latino
979 (5.0)
Education (N, %)
Grade 12 or Less
1,563 (16.5)
College, Technical or Vocational
2,794 (29.6)
Bachelor's Degree
2,552 (27.0)
Graduate or Professional Degree
2,469 (26.1)
Income (N, %)
Less than $20,000
1,294 (13.7)
$20,000 to $49,999
2,815 (29.8)
$50,000 to $79,999
2,251 (23.8)
$80,000 or More
2,758 (29.2)
Age (mean, sd)
50.2 (16.0)
All data on this website are reported from PEGS Data Freeze 3.1 created on
6/27/2023
.
Back
to Top
Last Reviewed: February 03, 2026
Skip Navigation
Study Participants
PEGS: Personalized Environment and Genes Study
Close the left navigation
Add
Home
About PEGS
Data Snapshots
Explore PEGS with i2b2
Frequently Asked Questions
Results Explorer
Study Data
Study Design
Study Participants
Scientific Collaborations
Collaboration Guidelines
Collaborative Studies
Policies and Process
Submit a Proposal
Leadership Team & Advisory Groups
News & Updates
Publications
Contact Us
PEGS was initially established as the Environmental Polymorphisms Registry, which was a cross-sectional cohort with participants selected by convenience sampling. In 2002, the Environmental Polymorphisms Pilot Study (EPPS) was established to assess willingness to participate in such a cohort and to determine the efforts that would be needed for recruitment. The goal of EPPS was to enroll 500 subjects through outpatient medical clinics in the UNC Healthcare System. Based on the favorable response rate, enrollment for EPR/PEGS began in 2005, with the goal of recruiting 20,000 individuals living in the greater Research Triangle Park (RTP) region in North Carolina who reflect the overall demographics of the area in terms of age, sex, race and ethnicity.
PEGS participants were recruited from outpatient clinics and hospitals in the region as well as from the general population at over 200 unique sites, including clinical centers, hospitals, corporate offices, community health fairs, career fairs, colleges and universities, charity walks and races, senior centers, sporting events, social clubs, religious institutions, military bases, festivals and other community events. The PEGS cohort comprises 19,445 participants, and enrollment is ongoing at the National Institute of Environmental Health (NIEHS)
Clinical Research Unit
(CRU) in North Carolina, the National Institutes of Health (NIH)
Clinical Center
in Maryland, the
PEGS enrollment website
and
Clinicaltrials.gov
. Except for the NIH Clinical Center in Maryland, all recruitment sites are in North Carolina.
Contact is maintained with PEGS participants through email, flyers and phone calls to update their personal information, reduce attrition and maximize response rates for follow-up studies. Current contact information is maintained on as many subjects as possible using a combination of annual mailings,
newsletters
, emails and telephone calls. Subjects agree to be contacted for follow-up studies for up to 25 years after enrollment.
Participant Demographics
Demographic Variable
Value
Sex (N, %)
Female
12,120 (62.3)
Male
7,298 (37.5)
Race (N, %)
White
12,279 (63.1)
Black or African American
5,361 (27.6)
Other
868 (4.5)
Ethnicity (N, %)
Non-hispanic / Non-latino
17,750 (91.3)
Hispanic Latino
979 (5.0)
Education (N, %)
Grade 12 or Less
1,563 (16.5)
College, Technical or Vocational
2,794 (29.6)
Bachelor's Degree
2,552 (27.0)
Graduate or Professional Degree
2,469 (26.1)
Income (N, %)
Less than $20,000
1,294 (13.7)
$20,000 to $49,999
2,815 (29.8)
$50,000 to $79,999
2,251 (23.8)
$80,000 or More
2,758 (29.2)
Age (mean, sd)
50.2 (16.0)
All data on this website are reported from PEGS Data Freeze 3.1 created on
6/27/2023
.
Back
to Top
Last Reviewed: February 03, 2026