An ensemble method based on marginal-effect models (EMM) for estimating usual food intake from single-day dietary data and internal/external two-day dietary data

The Relationship Between Diet Quality and 21-Year Cumulative Health Care Costs Among Australian Women: A Longitudinal Cohort Study

BACKGROUND

The relationships between diet quality and health care costs have not been explored beyond 15 years.

OBJECTIVE

To investigate relationships between both baseline diet quality and change in diet quality over time with cumulative data on health care claims and costs over 21 years among Australian women.

DESIGN

This is a secondary analysis of data from a cohort study, the Australian Longitudinal Study on Women's Health.

PARTICIPANTS/SETTING

Data for women born between 1946 and 1951 included diet quality data at baseline (2001, n = 8228), change in diet quality (2001-2013, n = 6553), and cumulative administrative health care data (2001-2021).

MAIN OUTCOMES

Diet quality was assessed using the Australian Recommended Food Score (ARFS) and the Fruit and Vegetable Variety Score. Twenty-one-year cumulative Medicare Benefits Schedule data (number of claims; total charges [$USD]), Australia's universal health care coverage, were reported by baseline ARFS quintile and category of diet quality change ("diet quality worsened" [ARFS decrease ≤ -4 points], "remained stable" [-3 ≤ change in ARFS ≤ 3 points] or "improved" [ARFS increase ≥ 4 points]).

STATISTICAL ANALYSIS

Linear regression analyses were conducted and adjusted for socioeconomic, health, and lifestyle factors.

RESULTS

Higher baseline vegetable ARFS were correlated with fewer 21-year cumulative Medicare claims (β = -4.9, 95% CI, -7.3, -2.4) and charges (β = -$214; 95% CI, -$341; -$88). Baseline higher dairy scores were correlated with higher Medicare claims (β = 17.2; 95% CI, 11.1, 23.3) and charges (β = $762; 95% CI, $448, $1076). Compared with women whose diet quality score remained stable, those whose diet quality worsened over time made significantly more claims and higher charges; median (Q1, Q3) 413 (277, 588) claims, $17 868 ($11 037, $27 808) cumulative charges, compared with 387 (259, 559) claims, and $16 953 ($10 033, $26 604) cumulative charges. Change in total ARFS and ARFS subscales were predictors of 21-year cumulative health care claims. For each 1-point increase in ARFS over time, 1.2 fewer health care claims were made (95% CI, 0.3-2.2). Increasing vegetable and dairy ARFS scores were correlated with significantly fewer claims.

CONCLUSIONS

Baseline greater variety of vegetables was correlated with fewer 21-year health care claims and costs. Worsening diet quality over time was correlated with greater cumulative health care claims and costs. Consideration of dietary quality and variety in national policy is suggested to potentially reduce national health care claims and costs.

Comparing Self-Reported Dietary Intake to Provided Diet during a Randomized Controlled Feeding Intervention: A Pilot Study

Systematic and random errors based on self-reported diet may bias estimates of dietary intake. The objective of this pilot study was to describe errors in self-reported dietary intake by comparing 24 h dietary recalls to provided menu items in a controlled feeding study. This feeding study was a parallel randomized block design consisting of a standard diet (STD; 15% protein, 50% carbohydrate, 35% fat) followed by either a high-fat (HF; 15% protein, 25% carbohydrate, 60% fat) or a high-carbohydrate (HC; 15% protein, 75% carbohydrate, 10% fat) diet. During the intervention, participants reported dietary intake in 24 h recalls. Participants included 12 males (seven HC, five HF) and 12 females (six HC, six HF). The Nutrition Data System for Research was utilized to quantify energy, macronutrients, and serving size of food groups. Statistical analyses assessed differences in 24 h dietary recalls vs. provided menu items, considering intervention type (STD vs. HF vs. HC) (Student's t-test). Caloric intake was consistent between self-reported intake and provided meals. Participants in the HF diet underreported energy-adjusted dietary fat and participants in the HC diet underreported energy-adjusted dietary carbohydrates. Energy-adjusted protein intake was overreported in each dietary intervention, specifically overreporting beef and poultry. Classifying misreported dietary components can lead to strategies to mitigate self-report errors for accurate dietary assessment.