Abstract P343: Do Foot Problems in Diabetes Portend Serious Consequences? Calibrating Risk by Comparing Mortality With Cardiovascular Disease Categories

Abstract

Patients with diabetic foot disease are predisposed to developing serious cardiovascular and other mortal events. Since it is not clear what the comparative risk for death among adults with diabetes and foot problems is, we conducted a formal analysis comparing these individuals with other established high-risk cardiovascular disease (CVD) categories. We analyzed data from the National Health Interview Survey’s (NHIS) sample adult files between 2001 and 2014. We used information on diabetes and podiatrist care to create a diabetes and foot disease (DFD) variable. Information regarding mortality, cause of death, and follow-up time were from the National Death Index-linked mortality files (maximum 15 years of follow-up). After initially computing mortality rates, we evaluated the independent effect of (DFD) and CVD categories (angina pectoris, coronary heart disease [CHD], heart attacks, heart failure [HF], and stroke) on death using multivariate Cox proportional hazards models that adjusted for age, sex, race, marital status, education, region, physical activity, diet habits, smoking, alcohol consumption, and obesity. Specifically, since our primary interest was in comparing (DFD) with established high-risk cardiovascular disease (CVD) categories, we directly compared (DFD) to the CVD conditions in question through separate Cox models while incorporating (DFD) and the CVD category of interest as 4-level variables and used DFD as referent. Analyses were with SAS 9.4 and incorporated the complex sampling to yield population estimates. Data from 421,106 U.S. adults between 2001 and 2014 were analyzed. There were 8,646 participants with (DFD) and 55,511 with prevalent CVD (angina pectoris 5,989, coronary heart disease 19,832, heart attack 15,065, heart failure 12,344, and stroke 12,434). Over the follow-up period, 1,961 (DFD), 1,173 angina, 4,734 CHD, 3,836 heart attack, 3,526 HF and 3,234 stroke participants died. The mortality rate (per 1000 person-years) was: (DFD) 62, angina 41, CHD 42, heart attack 68, HF 66 and stroke 72. When (DFD) was directly compared to CVD categories, the hazard ratio for death was 1.04 (95% CI 0.93, 1.22) for angina pectoris, 1.05 (95% CI 0.97, 1.14) for CHD, 1.14 (95% CI 1.03, 1.21) for heart attack, 1.15 (95% CI 0.87, 1.34) for HF, and 1.12 (95% CI 1.03, 1.22) for stroke. Individuals with diabetes and foot problems were at equivalent risk for mortality compared to angina or CHD, and at slightly lower mortality risk than heart attack, heart failure or stroke. This population-based analysis quantifies and calibrates the magnitude of the mortality-risk in patients with diabetes and foot disease by comparing it to CVD categories. Current recommendations for care and the structure of care may need to be further refined to match intensity of treatment to mortality risk.