The International Childhood Cardiovascular Cohort (i3C) consortium outcomes study of childhood cardiovascular risk factors and adult cardiovascular morbidity and mortality: Design and recruitment

Contemp Clin Trials. 2018 Jun:69:55-64. doi: 10.1016/j.cct.2018.04.009. Epub 2018 Apr 22.


Although it is widely thought that childhood levels of cardiovascular (CV) risk factors are related to adult CV disease, longitudinal data directly linking the two are lacking. This paper describes the design and organization of the International Childhood Cardiovascular Cohort Consortium Outcomes Study (i3C Outcomes), the first longitudinal cohort study designed to locate adults with detailed, repeated, childhood biological, physical, and socioeconomic measurements and a harmonized database. I3C Outcomes uses a Heart Health Survey (HHS) to obtain information on adult CV endpoints, using mail, email, telephone, and clinic visits in the United States (U.S.) and Australia and a national health database in Finland. Microsoft Access, REsearch Data Capture (REDCap) (U.S.), LimeSurvey (Australia), and Medidata™ Rave data systems are used to collect, transfer and organize data. Self-reported CV events are adjudicated via hospital and doctor-released medical records. After the first two study years, participants (N = 10,968) were more likely to be female (56% vs. 48%), non-Hispanic white (90% vs. 80%), and older (10.4 ± 3.8 years vs. 9.4 ± 3.3 years) at their initial childhood study visit than the currently non-recruited cohort members. Over 48% of cohort members seen during both adulthood and childhood have been found and recruited, to date, vs. 5% of those not seen since childhood. Self-reported prevalences were 0.7% Type 1 Diabetes, 7.5% Type 2 Diabetes, 33% hypertension, and 12.8% CV event. 32% of CV events were judged to be true. I3C Outcomes is uniquely able to establish evidence-based guidelines for child health care and to clarify relations to adult CV disease.

Keywords: Adult Cardiovascular disease; Childhood cardiovascular risk factors; Collaborative cohort study; Heart health survey; Longitudinal cardiovascular risk study.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Australia / epidemiology
  • Cardiovascular Diseases* / diagnosis
  • Cardiovascular Diseases* / epidemiology
  • Cardiovascular Diseases* / prevention & control
  • Child
  • Cohort Studies
  • Databases, Factual / statistics & numerical data
  • Diabetes Mellitus* / diagnosis
  • Diabetes Mellitus* / epidemiology
  • Female
  • Finland / epidemiology
  • Health Surveys / methods
  • Humans
  • Hypertension* / diagnosis
  • Hypertension* / epidemiology
  • Longitudinal Studies
  • Male
  • Outcome Assessment, Health Care
  • Patient Selection
  • Risk Factors
  • Socioeconomic Factors
  • United States / epidemiology