BACKGROUND: Food insecurity is associated with high morbidity and mortality and is typically measured with the 10-item US Adult Food Security Survey Module. Shorter instruments may capture similar information, but this has not been validated against mortality in general populations. METHODS: A nationally representative sample of individuals aged 20 to 74 years from the US National Health Interview Survey 2011 to 2018 was included, with deaths linked to the National Death Index through 2019. Cardiovascular disease deaths were ascertained by RESULTS: We included 218 136 National Health Interview Survey participants (mean age, 45.3 years
50.8% women). Over a mean 5.0-year follow-up, 7025 premature deaths were observed (1711 from cardiovascular disease). In multivariable-adjusted models, hazard ratios (95% CIs) for all-cause death were similar among food security instruments (10-item, 1.22 [1.13, 1.32]
6-item, 1.23 [1.13, 1.34]
and 2-item, 1.23 [1.14, 1.32]), and C statistics were identical (0.823). Hazard ratios (95% CIs) for cardiovascular disease deaths were also similar among food security instruments (10-item, 1.38 [1.17, 1.62]
6-item, 1.27 [1.07, 1.51]
and 2-item, 1.41 [1.20, 1.66]), and C statistics ranged from 0.852 to 0.853. In the National Health and Nutrition Examination Survey replication (n=37 027, mean 7.8-year follow-up), associations were attenuated and became not statistically significant after adjustment for several cardiometabolic intermediates, particularly enrollment in food assistance programs, diabetes, low diet quality, inadequate or excessive sleep, and depression. CONCLUSIONS: A 2-item food security instrument captures similar mortality risk information compared with 10- and 6-item instruments. Furthermore, potential intermediate cardiometabolic factors may explain associations between food insecurity and mortality.