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Dietary Diversity Predicts Type of Medical Expenditure in Elders

Published Online: December 20, 2013
Yuan-Ting Lo, PhD; Mark L. Wahlqvist, MD; Yu-Hung Chang, PhD; Senyeong Kao, PhD; and Meei-Shyuan Lee, DPH
Objectives: To assess the association between Dietary Diversity Scores (DDSs, range: 0-6 points) and medical service utilization and expenditures.

Study Design: Prospective cohort study.

Methods: The Elderly Nutrition and Health Survey in Taiwan (1999-2000) provided a 24-hour dietary recall for DDSs. National Health Insurance claims were linked for 1650 eligible elders. Generalized linear models were used to appraise the association between DDS and annual medical utilization and expenditures.

Results: Those with a higher DDS had lower medical service utilization and expenditures for emergencies and hospitalization. After adjustment for potential confounders, emergency and hospitalization expenditures for elders with a DDS of 6 were lower than those with a DDS of 3 or lower. However, for preventive care and dental services, the highest DDS of 6 predicted greater utilization (0.25 and 0.5 times) and expenditure (270 and 420 Taiwanese new dollars). Findings remained unchanged when those who died in the first year or had any medical utilizations and expenditures1 year prior to death were excluded.

Conclusions: Greater dietary diversity is associated with lower emergency and hospitalization utilization and expenditures, but not lower use of ambulatory services. There is a need for health services to develop a nutrition policy for nutritionally disadvantaged groups.

Am J Manag Care. 2013;19(12):e415-e423
In the formulation of health policy, economic factors have an inescapable role, but the medical costs of diet-related and nutritionally related diseases are rarely given attention. Yet the opportunities to reduce the burden and costs of this disease subset are considerable.1-3 Popkin and colleagues4 estimated that effects of unhealthy dietary habits in China contributed US $3.9 billion to  medical costs from 2000 to 2005. However, such research has tended to focus on single nutrients as contributors to costs rather than overall dietary patterns. In addition, estimates of the medical costs of nutritionally related and diet-related diseases depend on reliable attributions of risk and of disease prevalence, and on the governance of a country’s medical system. The deduced nutritional economics may, therefore, be very divergent.

Dietary quality5 can be represented by indices that provide evidential support for international and national dietary guidelines and recommendations.6 This is because better diet quality is associated with decreased morbidity and mortality.7 Food-based indicators, as simple measures of dietary quality, can be useful predictors of morbidity8 and longevity, even in those aged 65 years.9,10 The Dietary Diversity Score (DDS) developed by Kant and colleagues11 is a practical and simple tool for assessing dietary quality. The DDS is also a predictor of all-cause mortality in Taiwanese elderly.9

Taiwan’s National Health Insurance (NHI) program is a universal health insurance scheme financed by a mandatory means-related premium system. More than 99% of Taiwanese are enrolled.12,13 The NHI benefits are broad, including inpatient and outpatient care, pharmaceuticals, dental care, and catastrophic illness,13 but require copayments by users (waived for those defined as poor). Total medical care expenditure increased from Taiwanese new dollars (NT$) 288 billion in 2000 to NT $442 billion in 2010, or 6.5% of the gross domestic product.14 Without recourse to other government revenue, the program had an accumulated deficit of NT $22.9 billion at the end of June 2011.15 Analysts project that the National Health Expenditure will continue to rise as the population ages and costs increase.14 In the case of Taiwan, the NHI data for 2009 show that medical expenditure for people more than 65 years accounted for one-third of the country’s total medical expenses. In addition, the elderly have greater per capita healthcare expenses.16

The public health sector, which extends beyond the conventional healthcare system, has long promoted healthy diets. This sector’s settings provide an opportunity to consider whether better dietary quality can decrease healthcare expenditures. If so, this might motivate governments to maintain and develop dietary programs, and encourage citizens to adhere to healthy diets to reduce medical costs. Therefore, we investigated the association between dietary quality and medical care utilization and expenditures in older Taiwanese. The hypothesis was that better dietary quality among elders would reduce both overall medical expenditures and types of expenditures.

METHODS

Study Population


The national Elderly Nutrition and Health Survey in Taiwan is a cross-sectional survey that incorporates a multistage, stratified, clustered probability sampling scheme. Participants were community-dwelling seniors 65 years or older between 1999 and 2000. The study design has been published elsewhere.17 A household interview was carried out by trained interviewers. Out of a total of 1937 participants, 1911 with demographic information were interviewed face-to-face and were asked to provide a 24-hour dietary recall and their family recipes.18 In order to have a representative estimate of an individual’s dietary quality, 126 participants with unreasonably high or low total daily energy intakes (<500 or >3500 kcal/day in women, <800 or >4200 kcal/day in men19) were excluded, along with 2 participants on a liquid diet. Of this group, 1783 elders were linked to the National Death Registry up to December 31, 2008 (10-year follow-up) and NHI claim data up to December 31, 2006 (8-year follow-up). We excluded participants who had inaccurate death records, no NHI records because of incorrect personal identification numbers, or catastrophic illness before the interview. Beneficiaries of NHI who suffer a major disease receive a catastrophic illness certificate, which grants exemption from copayment. These claim data are recorded in a Registry of Catastrophic Illness Database, which forms a subpart of the NHI claim data.20,21 The final sample included 1650 participants for analysis (Figure 1). This study was approved by the ethics committees of both Academia Sinica and the National Health Research Institutes in Taiwan. All participants provided signed informed consent.

Participants’ Characteristics and Socioeconomic Status

Participants were grouped by age (65-69, 70-74, 75-79, and >80 years old). Participants were sampling from 13 regions (Hakka, Mountainous areas, Eastern, Penghu, Northern 1, Northern 2, Northern 3, Central 1, Central 2, Central 3, Southern 1, Southern 2, and Southern 3). Education (illiterate, primary and below, secondary education and above), household monthly income (NT $<15,000, NT $15,000-29,999, NT $30,000-49,999, NT $50,000), smoking (yes, no), alcohol drinking (yes, no), betel nut chewing (yes, no), and perceived health status (good, fair, poor) were obtained from the face-to-face interview at baseline. These variables provided the required covariates in the multivariable models.

Dietary Diversity Score

The DDS is based on the 24-hour dietary recall obtained during the household interview at baseline. It comprised 6 foods group and was scored on a scale of 0 to 6, with 1 point per food group consumed (with a minimum intake of a half serving a day to score). The 6 food groups (dairy, egg/bean/fish/meat, rice and grains, fruits, vegetables, and fat and oil) were in accordance with the Taiwanese Food Guide.22 Previous reports detail the DDS methodology.9,11

Annual Medical Utilization and Expenditures

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Issue: December 2013
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