Research Design

The Strong Heart Study is a longitudinal epidemiologic cohort study. 

In its initial stages, the SHS included three components.  The first was a survey to determine cardiovascular disease mortality rates from 1984 to 1994 among tribal members aged 35-74 years of age residing in the 3 study areas (the community mortality study).  The second was the clinical examination of 4,500 eligible tribal members.  The third component is the morbidity and mortality (M&M) surveillance of these 4,500 participants.  The SHS has completed three clinical examinations of the original Cohort (Phase I: 1989-1991; Phase II: 1993-1995; Phase III: 1998-1999, respectively).  Due to the importance of genetics in the occurrence of CVD, the SHS expanded into the genetic epidemiology area.  In the Phase III study, in addition to the Cohort examination, the study conducted a pilot family study.  The family pilot study recruited approximately 30 families (10 per field center) which consisted of more than 900 family members.  Due to the success of the pilot study, Phase IV was funded to conduct a full-blown family study to investigate the heritability of CVD and its risk factors and perform linkage analysis to localize genes that contribute to CVD risk.    In Phase IV, an additional 18 to 25 extended families (a total of about 900 members at least 15 years of age) were recruited from each of the field centers from 2001 – 2003.  This provides a total of 3,776 individuals from 94 families, of whom 825 are Phase III participants re-examined in Phase IV.