Health wellbeing and economics:
a critical review of the economic literature
of nutritional interventions
Giovanni Fattorea, Francesca Ferrèa, Michela Meregagliaa,
Elena Fattoreb, Carlo Agostonic
aCERGAS
Università Bocconi, Milano
bdepartment of Environmental Health Sciences
cDepartment of Maternale Health and Paediatric Sciences,
University of Milan
Unrestricted funding from Sorermatec (Ferrero);
thanks to dott. Roberto Menta and its mean
De Gustibus Disputandum
Non Est
Nutrition & Health Economics
11° World iHEA Conference
July 12-15 2015
Introduction
• Lifestyle changes related to diet have the potential to improve
health and reduce healthcare costs associated to obesity and other
diet-related conditions (e.g. CVDs, diabetes, cancer)
• Nutrition education is the traditional instrument adopted at
individual (i.e. counselling) or population level (e.g. mass-media
campaign, school-based interventions) to encourage healthy eating
• In recent years, new strategies have been implemented both at
national and local level
• Examples of such policies in the US include bans on the use of trans
fats in restaurants, taxes on sugary drinks and a proposal to limit
the sale of large sugary drinks (Barnhill and King, 2013)
• Food taxes - the so called ‘obesitax’ - have been proposed in several
European countries (i.e. Denmark, France, Hungary, United
Kingdom) (Devisch, 2013)
Introduction
• The evidence about the effectiveness (‘does it work?’) and costeffectiveness (‘is it worth the money’?) of such interventions is often
limited
• Traditional counselling programs face the issue of individuals’
adherence to the recommended diet and retention of health benefits in
the long term
• To date fiscal policies (taxes and subsidies) have been driven largely by
imperatives to rise revenue or increase supply rather than to change
population behaviours (Moodie et al., 2013)
• Moreover, cost consequences needed to be included in economic
evaluations of nutrition interventions may be broader than usually
applied in healthcare (e.g., individual food expenditure, agriculture
productivity) (Lenoir-Wijnkoop, 2011)
• Some policies (e.g., excluding unhealthy food from food assistance
programs) may also have undesirable consequences from an ethical
and social point of view (Barnhill and King, 2013; Devisch, 2013)
Introduction and objective of the study
• The increasing interest in policy actions aimed at improving people
diet suggests the crucial role of economic analysis of nutrition
interventions (Wong et al., 2011; Nuijten, 2011)
• The aim of our study is to summarize and critically assess economic
evaluation studies conducted on interventions (directly or indirectly)
aimed at voluntary dietary improvements
• We consider a number of nutrition interventions expected to
stimulate individuals to modify their nutrition behaviour (e.g.
nutritional counselling, information campaigns, food labelling and
fiscal measures)
Methods
• We perform a systematic literature review following the PRISMA
statement (Preferred Reporting Items for Systematic Reviews and
Meta-Analyses)
• Three electronic databases are searched: PubMed, OVID Medline
and EMBASE
• A combination of diet-related keywords (i.e., fat, diet, intake,
nutrition) and economic-related terms (i.e., cost-effectiveness, costutility, cost-benefit, health economics, economic evaluation) are
used
• The search is performed on titles and abstracts only; we filtered
only English full-text papers and literature published up to March 31,
2013
• All database search results are imported into EndNote software
(version 6) for the purpose of identifying duplicate papers and
title/abstract screening
Methods
Papers are considered for inclusion if they:
•
•
•
address voluntary diet interventions (either positive actions – i.e.,
introducing or increasing the consumption of a healthy food, or
negative actions – i.e., eliminating or reducing the consumption of a
harmful food)
report an economic evaluation of any sort (i.e. documenting both
clinical outcomes improving wellbeing and information about use of
scarce resources - costs)
are original studies (i.e., no review articles, meeting abstracts,
editorials)
Studies are assessed using the standard “checklist” for critical appraisal of
economic evaluation studies (Drummond, 2005) complemented with
the Consensus on Health Economic Criteria CHEC-list focusing on the
quality of economic evaluations (Evers et al., 2005)
Methods
Papers are considered for inclusion if they:
•
•
•
address voluntary diet interventions (either positive actions – i.e.,
introducing or increasing the consumption of a healthy food, or
negative actions – i.e., eliminating or reducing the consumption of a
harmful food)
report an economic evaluation of any sort (i.e. documenting both
clinical outcomes improving wellbeing and information about use of
scarce resources - costs)
are original studies (i.e., no review articles, meeting abstracts,
editorials)
Studies are assessed using the standard “checklist” for critical appraisal of
economic evaluation studies (Drummond, 2005) complemented with
the Consensus on Health Economic Criteria CHEC-list focusing on the
quality of economic evaluations (Evers et al., 2005)
Results
(flow chart)
265 Potentially relevant records identified by
searching electronic databases
PubMed (n= 83 )
Ovid MEDLINE (R) (n= 101)
EMBASE (n= 81)
103 Duplicates removed
162 Records screened
138 Records excluded after screening titles
and abstracts
24 Full-text retrieved and screened
14 Additional full texts retrieved after
screening the reference lists of relevant
review articles and the retrieved full
texts
38 Full-text screened and included in the
review
48 clinical nutrition
27 no nutritional intervention
20 no economic evaluation
15 review articles
8 maternal or infant under nutrition
7 commentary/editorial/ trial protocol
6 no full text available
5 no English papers
2 animal studies
Results
(country)
Studies use (or generate) data from the USA (n=16), European countries
(n=14), Australia (n=6), Chile (n=1) and Canada (n=1)
Netherlands, 4
Sweden, 1
Greece, 1
Germany, 2
USA, 16
France, 2
Finland, 1
UK, 2
Denmark, 1
Chile, 1
Canada, 1
Australia, 6
Results
(study design)
Experimental study
7
18
7
3



3
Experimental +
modelling
Quasi -experimental
study
Non - experimental
study
Modelling
Among modelling studies, Markov chains is the preferred approach (n=7) as
it is generally used to simulate chronic diseases progression
The experimental study group includes Randomized Control Trials (RCT;
n=4) and Cluster Randomized Control Trials (CRCT; n=3)
The non-experimental studies include one cross-sectional study and two
retrospective cohort studies
* Quasi-experimental studies indicate experiments with non-equivalent control group
Results
(nutritional intervention)
Low-fat diet
7
Salt intake reduction
1
16
1
Fruit and vegetable consumption
1
Low-calorie diet
2
Low-carbohydrate diet
Pre-prepared meals avoidance
5
Water intake
8


Not specified
A few studies (n=3) also combine two different primary interventions (e.g. low-fat diet
and salt reduction)
In 16 studies, main dietary interventions are associated with secondary interventions
targeting other health-related behaviours (i.e. physical activity, smoking and alcohol)
* Low-fat diets implicate reduction of fat intake or replacement of saturated fat (SFA) with polyunsaturated (PUFA)
Results
(policy instrument)
• Experimental and quasi-experimental studies usually adopt
nutritional counselling (i.e. traditional individual and/or group
lessons with a dietician or innovative instruments such as videolesson packets, picture books, home visits, phone discussions and email messages) in order to promote healthier diets and lifestyle
• One study assess the effects of a public information campaign
encouraging a switch from whole to skim milk
• Another one evaluate a TV advertising control programme of
energy-dense food and beverage
• Modelling studies often predict health-related and economic effects
of potential policy interventions such as banning industrial transfatty acids, raising taxes on a range of unhealthy food and
nutritional labelling
Results
(economic evaluation)
6
13
CEA
CUA
5
CBA
Combined design
14

Cost-effectiveness analysis (CEA): economic results are presented as cost per
unit of health gain (e.g., cost per case averted or cost per year of life gained)

Cost-utility analysis (CUA): the unit of benefit is expressed in terms of an index
capturing both quantity and quality of life (i.e. quality-adjusted life years – QALYs
– or disability adjusted life years – DALYs)

Cost-benefit analysis (CBA): both costs and benefits are expressed in monetary
terms
* Combined design indicates studies performing, for example, both CEA and CBA
Results
(study perspective)
• Healthcare perspective (n=20): a narrow perspective where only direct
medical costs (e.g. for laboratory test, treatment) are included
• Societal perspective (n=15): other costs are included, typically referring
to non-medical services (e.g., social care), productivity losses and time
spent by patients and caregivers
• Public sector perspective (n=3): the costs supported by government in
order to implement the nutrition intervention (e.g., media advertising,
loss of tax revenues, F&V stamps for low-income consumers) are
assessed
• The level of specification of cost analysis and the approach used for
cost measurement widely differ across studies
• Some studies limit their analysis to the intervention costs (e.g. for
screening and education), while others try to estimate industry costs
(e.g. product reformulation or labelling) resulting from the nutritional
policy
• Limited attempt to investigate the impact on the agri-food system
Results
(study outcomes)
• In order to assess the consequences of a nutritional intervention, 23
studies adopt a clinical endpoint (e.g., strokes prevented)
• 10 studies use a clinical surrogate (biomarker), such as systolic
blood pressure, high density lipoprotein, blood cholesterol, body
weight and BMI
• Five studies limit their outcome assessment to the direct nutritional
consequences of the intervention (e.g., fat, F&V, salt and other
nutrients intake; milk consumption).
• The diet or nutritional status of the study participants is assessed
through dietary questionnaires (e.g., diet diaries; 24-hour diet
recalls; food frequency questionnaires) or through health screening
measuring biomarkers (e.g., blood cholesterol) of nutrient intake
Results
(study results)
• Most studies conclude that the intervention examined, compared to
the alternative one or the status quo, is cost-saving (n=21) or costeffective (n=10)
• A few articles (n=7) conclude that the intervention concerned is not
cost-effective or that health outcome improvements are negligible
• Some equity aspects are present in a few papers: 5 studies conduct
sub-group analyses (by race, gender, age, income, education,
marital status and health condition) and other 9 studies focus on
ethnic minority (e.g. Alaskan) or low socio-economic groups
• No study discuss the equity implications of interventions that may
impose additional private expenditure to household
Discussion: the state of the art of the economic
evaluation of nutrition interventions
• Only 38 published studies performing an economic evaluation of
interventions aimed at improving nutritional habits have been
identified
• Given the potential of health gains of these interventions, the
limited number studies is alarming and signals that policies cannot
based on adequate evidence
• Moreover, nutritional interventions have many socio-economic
implications that need to be considered in the evaluation of their
effectiveness
• Without valid and reliable assessments of wellbeing effects and
resources uses attributable to interventions aimed at changing
human habits the risk of policy failure, in conception and
implementation, is very real
Discussion: tow major weaknesses in empirical
research
In particular, two methodological weaknesses arise from the reviewed
articles:
1. Modelling is the dominant evaluation strategy, but models are not
always populated with data obtained from valid empirical studies
→ models risk to be mere speculations
2. Methodologies and guidelines developed for the economic
evaluation of healthcare interventions are followed by the vast
majority of studies, but traditional health technologies are different
from nutrition interventions
Discussion: specificities of nutrition
interventions
1.
2.
3.
4.
Nutrition habits are culturally and socially embedded and differ
substantially from medical services → need to evaluate how to
induce behavioural changes rather than simply investigate the
comparative benefits of nutrients on human health (health is not the
only motivation of eating)
Food expenses are generally private and not part of a public
healthcare budget → the relevant constraint in this case is the
available income (the framework of cost-effectiveness may be
inadequate)
Equity issues: if healthier diets require additional expenses or anyway
interventions create additional financial burdens, policies have
different economic implications across socio-economic groups
Agriculture and food industry implications: higher demand for
healthier food can boost domestic production or imports → significant
economic impacts (e.g., level of trades, price of food) between and
within nations