Eliminating Food Insecurity in the USA: a Target Trial Emulation Using Observational Data to Estimate Effects on Health-Related Quality of Life

Association of food insecurity with mental health status, mental health services utilisation and general healthcare utilisation among US adults

BACKGROUND

Food insecurity poses a substantial threat to mental health. However, there is limited understanding of how food-insecure adults experience mental health challenges and access necessary health services. We examined the association of food insecurity with mental health status, mental health service utilisation and general healthcare utilisation among US adults.

METHODS

A retrospective longitudinal cohort study was conducted to analyse data from 9906 US adults participating in the 2016-2017 Medical Expenditure Panel Survey. Outcomes included mental health status, mental health service utilisation and general healthcare utilisation. The primary independent variable was food insecurity measured using the 10-item Food Security Survey Module. Two separate models were used: A lagged-dependent model and a fixed-effect model.

RESULTS

The lagged dependent model showed that food insecurity in 1 year was associated with a higher likelihood of reporting mental health symptoms based on the Patient Health Questionnaire and the Kessler 6 Psychological Distress Scale (3.5 percentage points (95% CI: 1.3 to 5.8)) and self-reported poor mental health (5.8 percentage points (2.9 to 8.7)) in the subsequent year. However, compared with food-secure adults, food-insecure adults were no more likely to have outpatient mental health visits, specialty mental health visits or psychotropic medication fills. Moreover, food-insecure adults were 4.1 (1.2 to 7.0) percentage points more likely to have an emergency room visit than food-secure adults. These findings were consistent with the fixed-effect model.

CONCLUSION

Food insecurity is associated with worse mental health. However, food-insecure adults may not access adequate mental health services and instead rely on emergency room visits.

Estimating the Effect of Adhering to the Recommendations of the 2019 Canada's Food Guide on Health Outcomes in Older Adults: Protocol for a Target Trial Emulation

BACKGROUND

The 2019 Canada's Food Guide provides universal recommendations to individuals aged ≥2 years. However, the extent to which these recommendations are appropriate for older adults is unknown. Although ideal, conducting a large randomized controlled trial is unrealistic in the short term. An alternative is the target trial emulation framework for causal inference, a novel approach to improve the analysis of observational data.

OBJECTIVE

This study aims to describe the protocol for a target trial emulation in older adults, with an emphasis on key aspects of a hypothetical sustained diet and physical activity intervention.

METHODS

To emulate the target trial, nonexperimental data from the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge; N=1753 adults aged ≥67 years) will be used. NuAge includes 4 yearly measurements of dietary intakes, covariates, and outcomes. The per-protocol causal contrast will be the primary causal contrast of interest to account for nonadherence. The sustained intervention strategy will be modeled using the parametric g-formula. In the hypothetical trial, participants will be instructed to meet sex-specific minimal intakes for vegetables and fruits, whole grains, animal- and plant-based protein foods, milk and plant-based beverages, and unsaturated fats. The eligibility criteria, follow-up, intervention, outcomes, and causal contrast in the emulation will closely align with those of the target trial, with only minor modifications. We will attempt to emulate the randomization of treatment by adjusting for baseline covariates and prebaseline dietary habits.

RESULTS

Data collection for NuAge was completed in June 2008. For this study, the main analysis was started in May 2024. Submission of the manuscript is expected by February 2025.

CONCLUSIONS

Emulating a target trial will provide the first evidence of the adequacy of the 2019 Canada's Food Guide recommendations for older adults in relation to health outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/65182.

Estimating the impact of addressing food needs on diabetes outcomes

Objective

To estimate the association between food needs and diabetes outcomes.

Research design and methods

Longitudinal cohort study, using a target trial emulation approach. 96,792 adults with type 2 diabetes mellitus who underwent food need assessment in a network of community-based health centers were followed up to 36 months after initial assessment. We used targeted minimum loss estimation to estimate the association between not experiencing food needs, compared with experiencing food needs, and hemoglobin a1c (HbA1c), systolic and diastolic blood pressure (SBP and DBP), and LDL cholesterol. The study period was June 24th, 2016 to April 30th, 2023.

Results

We estimated that not experiencing food needs, compared with experiencing food needs, would be associated with 0.12 percentage points lower (95% Confidence Interval [CI] -0.16% to -0.09%, p = < 0.0001) mean HbA1c at 12 months. We further estimated that not experiencing food needs would be associated with a 12-month SBP that was 0.67 mm Hg lower (95%CI -0.97 to -0.38 mm Hg, p < .0001), DBP 0.21 mm Hg lower (95%CI -0.38 to -0.04 mm Hg, p = .01). There was no association with lower LDL cholesterol. Results were similar at other timepoints, with associations for HbA1c, SBP, and DBP of similar magnitude, and no difference in LDL cholesterol.

Conclusions

We estimated that not experiencing food needs may be associated with modestly better diabetes outcomes. These findings support testing interventions that address food needs as part of their mechanism of action.

Social Isolation, Loneliness, and Quality of Life Among Food-Insecure Adults

INTRODUCTION

Food insecurity is associated with adverse health outcomes, but may also have a detrimental effect on social relationships, potentially exacerbating social isolation and loneliness, and consequently affecting health-related quality of life. This study examined the associations of food insecurity with social isolation, loneliness, and health-related quality of life among U.S. adults.

METHODS

A retrospective cohort study was conducted using panel data from the 2020-2021 Medical Expenditure Panel Survey. Regression models were used to assess the associations of food insecurity in 1 year with the outcomes of interest in the subsequent year while adjusting for baseline individual-level characteristics. Analysis was conducted in December 2023.

RESULTS

Experiencing food insecurity in 2020 was significantly associated with increased reports of social isolation (3.1 percentage points [95% CI: 1.2-5.1]) and loneliness (9.7 percentage points [95% CI: 1.0-18.3]) in 2021. Additionally, food insecurity in 2020 was significantly associated with lower self-reported good mental health (-2.9 percentage points [95% CI: -5.1, -0.6]) and mental component summary score from the Short Form-12 Health Survey (-3.3 points [95% CI -3.8, -2.9]) in 2021. However, there were no or small associations with physical health-related quality of life.

CONCLUSIONS

Food insecurity is associated with worse social and mental well-being among U.S. adults. This suggests that food insecurity interventions should not focus too narrowly on nutrition, but instead give holistic consideration to the multiple ways food insecurity harms health-not only via lower quality diets, but through worse mental health and impairing the ability to participate in social life.