Educational Disparities in Mortality Among Adults With Diabetes in the U.S.

OBJECTIVE: To measure relative and absolute educational disparities in mortality among U.S. adults with diabetes and to compare their magnitude with disparities observed within the nondiabetic population. RESEARCH DESIGN AND METHODS: A total of 85,867 individuals (5,007 with diabetes), aged 35–84 years, who participated in the National Health Interview Survey from 1986 to 1996 were followed for mortality through 31 December 2002. Relative and absolute educational disparities in all-cause, cardiovascular disease (CVD), and non-CVD mortality were measured. RESULTS: In relative terms, the risk of all-cause mortality was 28% higher in diabetic adults with the lowest versus the highest position on the educational scale (relative index of inequality 1.28 [95% CI 1.08–1.53]). This inverse relationship reflected marked disparities in CVD mortality and was found in all age, sex, and race/ethnicity groups except Hispanics. Although substantial, this relative educational gradient in mortality among adults with diabetes was smaller than in the nondiabetic population. In absolute terms, diabetic adults with the lowest position on the educational scale suffered 503 excess deaths per 10,000 person-years of follow-up compared with those with the highest position. These absolute disparities were stronger than in the nondiabetic population. The results were even more striking for CVD mortality. CONCLUSIONS: The risk of mortality differs substantially according to educational level among individuals with diabetes in the U.S. Although relative educational disparities in mortality are weaker in adults with versus without diabetes, their absolute impact is greater and translates into a major mortality burden.