METHODS

To estimate the direct health-related costs attributable to food insecurity in 2014, we reviewed empirical research literature published in peer-reviewed journals from approximately 2005 to 2015, searching for quantitative findings of associations between food insecurity and health outcomes. We specifically searched for quantitative findings that involved either odds ratios (most often), likelihood ratios, or relative risk ratios expressing the differences in likelihood of a person living in a food insecure household having a disease or disease condition compared to a person living in a food-secure household (food security status is the exposure variable).

Those probability ratios were then translated into population attributable fractions (PAFs) expressing the proportion of the total prevalence of the disease in the population attributable to food insecurity (i.e., the excess fraction attributable to food insecurity). As noted above, this process requires the assumption that food insecurity is causally related to the disease conditions.

In case-control studies, if adjusted odds ratios (ORs) are available, they can be transformed into relative risk ratios using formula 1 below: 1. RR = OR/[(1-Po)+(Po*OR)], where RR is the relative risk ratio, OR is the odds ratio, and Po is the proportion of the unexposed (food secure) who develop the outcome, or become cases. This adjustment is desirable since, though the OR is an acceptable estimate of the Relative Risk ratio (RR) in case-control studies, and approaches RR in the situation of rare diseases in which very few of the unexposed develop the disease, the higher the prevalence of the disease in the unexposed population (e.g., the food-secure population), the greater the deviation of the RR from the OR.

With the relative risk ratios thus calculated (or if they are available), they can be used to calculate estimates of the excess population attributable fractions (PAF) of the diseases arising due to exposure to the predictor, food insecurity, using formula 2 below: 1. PAF = Pe (RR - 1) / [Pe (RR - 1) + 1] * 100%, where PAF is the excess population attributable fraction of disease in the population considered to result from the presence of the exposure variable or condition (i.e., food insecurity), RR is the relative risk ratio calculated as above, and Pe is the proportion of controls (those who do not have the outcome or disease) who were exposed (live in a food-insecure household).

A complete table of all the conditions for which we found new studies providing the information needed to calculate attributable fractions can be found in Appendix Exhibit A1 in the PDF version of this report. For most of the health conditions, the attributable fraction (AF) is relatively small, 10 percent or less. For a few conditions we found research results leading to more than one AF for a condition. In those cases, we either used the average of the AFs, or used the one which was more reliable for the specific age group and condition under consideration. And for a few conditions, we were either unable to find data on the prevalence and number of people in the relevant sub-population with the condition, or data on the cost of treating cases of the condition. In those few instances, we were unable to estimate the disease burden or the costs. This was particularly true when the condition was failure to receive recommended or prescribed treatment, or treatment foregone due to inability to pay as a result of food insecurity.

For a couple of conditions (e.g., PEDS concerns; parents report of developmental concerns about their child), we had to add an additional link to the chain of logic such as obtaining positive predictive value of the indicator (PEDS concerns) and the outcome (special education). With a few conditions for which we could not find needed prevalence data, we relied on data from the U.S. Census Bureau on relationships between reported health status and health services utilization.

Using the information in Exhibit 1A, together with data from the Agency for Healthcare Research and Quality's Medical Expenditure Panel Survey (MEPS, or other national survey data) on the number of cases of each disease condition in the population in 2014 (when available), we estimated the fraction (proportion) of cases of each health condition attributable to food insecurity. Combining the results of these calculations with data on annual expenditures for treatment of individuals with the condition (from MEPS or other national health surveys), we estimated the total annual direct costs of treatment for all individuals with the condition.

Data on numbers of hospitalizations, and average costs of hospital stays were obtained from the Agency for Healthcare Research & Quality's Healthcare Cost & Utilization Project public access data obtained via the HCUPnet online query system (http://hcupnet.ahrq. gov/). Data were obtained from both the HCUP National Inpatient Database and the HCUP Kids' Inpatient Database. Several price index series were used to adjust the price of various healthcare services. These price indices were taken from the Bureau of Labor Statistics' online databases (http://www.bls.gov/cpi/). Resulting estimated costs for each condition are presented in Appendix Exhibit 2 of the PDF version of this report.

The Brandeis researchers estimated the cost of the private food assistance system at $17.8 billion in 2010 ($19.52 billion in 2014 dollars), and we calculated the total cost of the public food assistance system to be $103.55 billion in 2014. However discussions with healthcare colleagues and others led us to the position that the costs of these two complementary food assistance systems are more accurately viewed as the costs of prevention of food insecurity, not as a cost of food insecurity itself. The costs of these two food assistance systems are the costs of the vaccine that prevents food insecurity and hunger from occurring in the nation's households, families and children. Thus the costs of these two systems are not included as costs attributable to food insecurity.

For more information on methods, download the full study.

Sources

  1. Shepard D, Setren E, Cooper D. Hunger in America, Suffering We All Pay For Center for American Progress; 2011.
  2. Coleman-Jensen A, Rabbitt M, Gregory C, Singh A. Household Food Security in the United States in 2014, ERR-194: U.S. Department of Agriculture, Economic Research Service; September 2015.
  3. Zhang J, Yu KF. What’s the relative risk? A method of correcting the odds ratio in cohort studies of common outcomes. JAMA 1998;280(19):1690-1.
  4. Hennekens C, Buring J. Epidemiology in Medicine. Boston/Toronto: Little Brown & Company; 1987.
  5. O’Hara B, Caswell K. Health Status, Health Insurance, and Medical Services Utilization: 2010: US Census Bureau; July 2013.
  6. Hamilton W, Cook J, Thompson W, Buron L, Frongillo Jr E, Olson C, et al. Household Food Security in the United States in 1995: Summary Report of the Food Security Measurement Project. In. Alexandria, VA; 1997.
  7. Maslow A. A theory of human motivation. Psychological Review 1943; 50:26.
  8. Bourre JM. Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients. J Nutr Health Aging 2006; 10(5):377-85.
  9. Rice D, Barone S. Critical periods of vulnerability for the developing nervous system: evidence from humans and animal models. Environ Health Perspect 2000;108 Suppl 3:511-33.
  10. Shonkoff J, Phillips D. From Neurons to Neighborhoods: The Science of Early Childhood Development.; Available from: http://www.nap.edu/openbook.php?record_id=9824&page=R1
  11. Coleman-Jensen A, Gregory C, Singh A. Household Food Security in the United States in 2013: Statistical Supplement: U.S. Department of Agriculture, Economic Research Service 2014.
  12. Grossman J, Mackenzie FJ. The randomized controlled trial: gold standard, or merely standard? Perspect Biol Med 2005;48(4):516-34.
  13. Tarasuk V, Cheng J, de Oliveira C, Dachner N, Gundersen C, Kurdyak P. Association between household food insecurity and annual health care costs. CMAJ 2015.
  14. Brown J, Shepard D, Martin T, Orwat J. The Economic Cost of Domestic Hunger; Estimated Annual Burden to the United States: An analysis commissioned by The Sodexho Foundation, in partnership with The Public Welfare Foundation and Spunk Fund, Inc 2007.
  15. Kosanovich K, Sherman E. Trends in Long-term Unemployment: US Bureau of Labor Statistics; 2015.
  16. US Bureau of Labor Statistics. Available from: http://data.bls.gov.
  17. Economic Report of the President. 2015: US Government Publishing Office.
  18. Nord M, Prell M. Food Security Improved Following the 2009 ARRA Increase in SNAP Benefits: U.S. Department of Agriculture, Economic Research Service; 2011.
  19. Cook JT, Frank DA, Berkowitz C, Black MM, Casey PH, Cutts DB, et al. Food Insecurity is associated with adverse health outcomes among human infants and toddlers. The Journal of Nutrition 2004; 134(6):1432-1438.
  20. Rose-Jacobs R, Black MM, Casey PH, Cook JT, Cutts DB, Chilton M, et al. Household Food Insecurity: Associations with at-risk infant and toddler development. Pediatrics 2008;121(1):65-72.
  21. Cook JT, Black M, Chilton M, Cutts D, Ettinger de Cuba S, Heeren TC, et al. Are food insecurity’s health impacts underestimated in the U.S. population? Marginal food security also predicts adverse health outcomes in young U.S. children and mothers. Adv Nutr 2013; 4(1):51-61.
  22. Skalicky A, Meyers AF, Adams WG, Yang Z, Cook JT, Frank DA. Child food insecurity and iron deficiency anemia in low-income infants and toddlers in the United States. Maternal and Child Health Journal 2006; 10(2):177-185.
  23. Black MM, Quigg AM, Cook J, Casey PH, Cutts DB, Chilton M, et al. WIC participation and attenuation of stress-related child health risks of household food insecurity and caregiver depressive symptoms. Arch Pediatr Adolesc Med 2012; 166(5):444-51.
  24. Leung CW, Epel ES, Willett WC, Rimm EB, Laraia BA. Household food insecurity is positively associated with depression among low-income supplemental nutrition assistance program participants and income-eligible nonparticipants.
  25. J Nutr 2015;145(3):622-7. 25. Ma CT, Gee L, Kushel MB. Associations between housing instability and food insecurity with health care access in low-income children. Ambul Pediatr 2008; 8(1):50-7.
  26. Park CY, Eicher-Miller HA. Iron deficiency is associated with food insecurity in pregnant females in the United States: National Health and Nutrition Examination Survey 1999-2010. J Acad Nutr Diet 2014; 114(12):1967-73.
  27. Parks CG, D’Aloisio AA, DeRoo LA, Huiber K, Rider LG, Miller FW, et al. Childhood socioeconomic factors and perinatal characteristics influence development of rheumatoid arthritis in adulthood. Ann Rheum Dis 2013; 72(3):350-6.
  28. Tayie FA, Zizza CA. Food insecurity and dyslipidemia among adults in the United States. Prev Med 2009; 48(5):480-5.
  29. Seligman HK, Bindman AB, Vittinghoff E, Kanaya AM, Kushel MB. Food insecurity is associated with diabetes mellitus: results from the National Health Examination and Nutrition Examination Survey (NHANES) 1999- 2002. J Gen Intern Med 2007; 22(7):1018-23.
  30. Berkowitz SA, Gao X, Tucker KL. Food-insecure dietary patterns are associated with poor longitudinal glycemic control in diabetes: results from the Boston Puerto Rican Health study. Diabetes Care 2014;37(9):2587-92.
  31. Beydoun MA, Wang Y. Pathways linking socioeconomic status to obesity through depression and lifestyle factors among young US adults. J Affect Disord 2010;123(1-3):52-63.
  32. Carmichael SL, Yang W, Herring A, Abrams B, Shaw GM. Maternal food insecurity is associated with increased risk of certain birth defects. J Nutr 2007;137(9):2087-92.
  33. Chi DL, Masterson EE, Carle AC, Mancl LA, Coldwell SE. Socioeconomic status, food security, and dental caries in US children: mediation analyses of data from the National Health and Nutrition Examination Survey, 2007-2008. Am J Public Health 2014; 104(5):860-4.
  34. Fitzgerald N, Hromi-Fiedler A, Segura-Pérez S, Pérez-Escamilla R. Food insecurity is related to increased risk of type 2 diabetes among Latinas. Ethn Dis 2011; 21(3):328-34.
  35. Whitaker RC, Phillips SM, Orzol SM. Food insecurity and the risks of depression and anxiety in mothers and behavior problems in their preschool-aged children. Pediatrics 2006; 118(3):e859-e868.
  36. Laraia BA, Siega-Riz AM, Gundersen C. Household food insecurity is associated with self-reported pregravid weight status, gestational weight gain, and pregnancy complications. J Am Diet Assoc. 2010; 110(5):692-701.
  37. Berkowitz SA, Baggett TP, Wexler DJ, Huskey KW, Wee CC. Food insecurity and metabolic control among U.S. adults with diabetes. Diabetes Care 2013; 36(10):3093-9.