The Health Examinees (HEXA) Study: Rationale, Study Design and Baseline Characteristics

Background: Korea has experienced rapid economic development in a very short period of time. A mixtureof traditional and modern risk factors coexists and the rapid change in non-genetic factors interacts withgenetic constituents. With consideration of these unique aspects of Korean society, a large-scale genomic cohortstudy-the Health Examinees (HEXA) Study-has been conducted to investigate epidemiologic characteristics,genomic features, and gene-environment interactions of major chronic diseases including cancer in the Koreanpopulation. Materials and
Methods: Following a standardized study protocol, the subjects were prospectivelyrecruited from 38 health examination centers and training hospitals throughout the country. An interviewbasedquestionnaire survey was conducted to collect information on socio-demographic characteristics, medicalhistory, medication usage, family history, lifestyle factors, diet, physical activity, and reproductive factors forwomen. Various biological specimens (i.e., plasma, serum, buffy coat, blood cells, genomic DNA, and urine) werecollected for biorepository according to the standardized protocol. Skilled medical staff also performed physicalexaminations.
Results: Between 2004 and 2013, a total of 167,169 subjects aged 40–69 years were recruited forthe HEXA study. Participants are being followed up utilizing active and passive methods. The first wave of activefollow-up began in 2012 and it will be continued until 2015. The principal purpose of passive follow-up is basedon data linkages with the National Death Certificate, the National Cancer Registry, and the National HealthInsurance Claim data.
Conclusions: The HEXA study will render an opportunity to investigate biomarkers ofearly health index and the chronological changes associated with chronic diseases.