title: Validation of PhenX measures in the personalized medicine research project for use in gene/environment studies.
abstract: BACKGROUND
  The purpose of this paper is to describe the data collection efforts and validation of PhenX measures in the Personalized Medicine Research Project (PMRP) cohort.
  
  
  METHODS
  Thirty-six measures were chosen from the PhenX Toolkit within the following domains: demographics; anthropometrics; alcohol, tobacco and other substances; cardiovascular; environmental exposures; cancer; psychiatric; neurology; and physical activity and physical fitness. Eligibility criteria for the current study included: living PMRP subjects with known addresses who consented to future contact and were not currently living in a nursing home, available GWAS data from eMERGE I for subjects where age-related cataract, HDL, dementia and resistant hypertension were the primary phenotypes, thus biasing the sample to the older PMRP participants. The questionnaires were mailed twice. Data from the PhenX measures were compared with information from PMRP questionnaires and data from Marshfield Clinic electronic medical records.
  
  
  RESULTS
  Completed PhenX questionnaires were returned by 2271 subjects for a final response rate of 70%. The mean age reported on the PhenX questionnaire (73.1 years) was greater than the PMRP questionnaire (64.8 years) because the data were collected at different time points. The mean self-reported weight, and subsequently calculated BMI, were less on the PhenX survey than the measured values at the time of enrollment into PMRP (PhenX means 173.5 pounds and BMI 28.2 kg/m2 versus PMRP 182.9 pounds and BMI 29.6 kg/m2). There was 95.3% agreement between the two questionnaires about having ever smoked at least 100 cigarettes. 139 (6.2%) of subjects indicated on the PhenX questionnaire that they had been told they had a stroke. Of them, only 15 (10.8%) had no electronic indication of a prior stroke or TIA. All of the age-and gender-specific 95% confidence limits around point estimates for major depressive episodes overlap and show that 31% of women aged 50-64 reported symptoms associated with a major depressive episode.
  
  
  CONCLUSIONS
  The approach employed resulted in a high response rate and valuable data for future gene/environment analyses. These results and high response rate highlight the utility of the PhenX Toolkit to collect valid phenotypic data that can be shared across groups to facilitate gene/environment studies.
authors.affiliation: Division of Research, Essentia Institute of Rural Health, 502 East Second Street, Duluth, MN 55805, USA. cmccarty@eirh.org.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: McCarty
authors.forename: Richard
authors.initials: R
authors.lastname: Berg
authors.forename: Carla M
authors.initials: CM
authors.lastname: Rottscheit
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Waudby
authors.forename: Terrie
authors.initials: T
authors.lastname: Kitchner
authors.forename: Murray
authors.initials: M
authors.lastname: Brilliant
authors.forename: Marylyn D
authors.initials: MD
authors.lastname: Ritchie
mesh_terms: D000437:Alcoholism / Q000235:genetics; D003625:Data Collection; D003710:Demography; D003865:Major Depressive Disorder / Q000235:genetics; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008875:Middle Aged; D010641:Phenotype; D057285:Precision Medicine; D015203:Reproducibility of Results; D057566:Self Report; D012907:Smoking / Q000235:genetics; D020521:Stroke / Q000235:genetics; D011795:Surveys and Questionnaires; D057170:Translational Research, Biomedical