A Markov model was built to analyze the cost-effectiveness of three obesity treatment strategies in Brazil: diet alone, diet plus sibutramine, and diet plus orlistat. Diet plus orlistat was the most effective strategy but diet plus sibutramine had the lowest incremental cost-effectiveness ratio. Although sibutramine had a lower ICER, its use is banned in some countries and diet alone was recommended due to small differences in effectiveness and cost. Sensitivity analyses showed initial utility values had the biggest impact on the model.

1. COST-EFFECTIVENESS ANALYSIS OF DRUGS USED IN OBESITY
TREATMENT IN BRAZIL, UNDER HEALTH SYSTEM PERSPECTIVE
Vianna C.M.M1
; Fernandes R.R.A1
; Mosegui G.B.G2
; Oliveira F.S.G1
1
Universidade do Estado do Rio de Janeiro (UERJ) – IMS
2
Universidade Federal Fluminense (UFF) - ISC
ABSTRACT
INTRODUCTION: During 1974 to 2009, the prevalence of overweight has increased 3 times in
males and twice in females in Brazil. In 2001, the cost of hospitalizations in the public health
system for overweight treatment and its co-morbidities achieved U$36 million, but in 2012, this
value raised to U$210 million measuring the cost of all diseases associated with overweight.
OBJECTIVES: Present a cost-effectiveness analysis comparing: (a) Diet; (b) diet plus
sibutramine and (c) diet plus orlistat, under the public health system perspective.
METHODS: A Markov model that simulates related obesity comorbidities as chronicle heart
disease and diabetes mellitus was build. Discount rate assumed was 5% and the outcome
data was taken from international literature and was measured by QALY. Direct cost was
calculated by the authors using data from public health system databases, as well as in related
cost studies made in Brazil.
RESULTS: Orlistat + diet was the most effective strategy, but Sibutramine + Diet had the lower
ICER (R$1.366.46). Sensitive variables showed in Tornado Diagram tested in a Univariate
sensitivity analysis showed not to modify the model final responses.
CONCLUSION: Regarding the low difference in effectiveness between only Diet and Diet +
Sibutramine, and the fact that this drug is forbidden in U.S. and Europe, this study
recommends the use of only Diet to treat Obesity, despite the very low value o Sibutramine
ICER.
METHODS
A Markov model was built based on Ara (2012) epidemiological model, where the enhance of
the BMI and the comorbidities events, influence directly the quality of life and so the
effectiveness of the different interventions. Figure 1 shows this interrelationships. Figure 2
shows the basic structure of the Markov Model. Direct cost values were extracted from
Brazilian cost studies. A Tornado Diagram was built and also a deterministic sensitivity
analysis.
Figure 1 – Interrelationships of the model variables. Figure 2 – Basic Markov model scheme
• Model Assumptions:
• Every patient had 35 years old, 1,7m height and 35 Body Mass Index (BMI) before the
intervention
• Patient weight that responded to pharmacological (Orlistat + Diet or Sibutramine + Diet)
treatment increase at the same rate in the first three years, than this rate decreases.
• Utility rates varies as a function of BMI levels and co-morbidities events. Only Diabetes
and Myocardial Infarction was considered as co-morbidities.
• Time horizon was 10 years, discount rate was 5% and Health System Perspective was
adopted.
METHODS (CONTINUED)

2. RESULTS CONCLUSIONS
REFERENCES
Although Brasil does not have a delimited acceptability threshold for technology incorporation
in the Health System, the World Health Organization (WHO) suggests three times GDP per
capita. This value is around U$35,100.00. Thus, both ICER (Sibutramine and Orlistat) can be
found under this threshold. Although Sibutramine + Diet has the lower one, both technologies
has an acceptable ICER to incorporation. Besides that consideration, the costs and
efffectiveness differences between Diet+ Sibutramine and only Diet are low.
Considering that Sibutramine comercialization is forbidden in Europe and U.S. - which may
lead us to assume some risks in adopting this strategy – and the low difference between this
costs and health results, the only Diet strategy appear to be the most adequate to adopt.
Efffectiveness studies with brazilian population as well as studies that makes more clear the
risks of sibutramine are also recommended to clarify the conclusions of the present work.
Strategy Cost (U$) Incr. Cost (U$) Efec.(QALY)
Incr.Efec.
(QALY)
ICER
(U$/QALY)
Diet 339.32 0.00 6.86 0.0000 0.00
Sibutramine +
Diet
398.20 58.88 6.99 0.136 430.41
Orlistat + Diet 718.22 320.02 7.12 0.130 2,449.10
The most effective strategy was Diet + Orlistast with an incremental effectiveness of 0,13.
Although the lower ICER (U$430,41) was from Diet + Sibutramine, representing the most
cost efffective alternative. The following table show model numbers.
Table 1. Cost effectiveness results of Markov Model
Tornado Diagram results showed that the initial Utility was the variable that has the major
impact on the model. A predictable fact as this variable is the core of all model equations.
Variations of it, did not affected final model responses.
COST-EFFECTIVENESS ANALYSIS OF DRUG USED IN OBESITY
TREATMENT IN BRAZIL, UNDER HEALTH SYSTEM PERSPECTIVE
Vianna C.M.M1
; Fernandes R.R.A1
; Mosegui G.B.G2
; Oliveira F.S.G1
1
Universidade do Estado do Rio de Janeiro (UERJ) – IMS
2
Universidade Federal Fluminense (UFF) - ISC
Ara R, L Blake, L Gray, M Hernández,M Crowther, A Dunkley, F Warren, R Jackson, A Rees, M Stevenson, K Abrams, N Cooper, M Davies, K Khuntiand A Sutton; What is the clinical effectiveness and cost-effectiveness of
using drugs in treating obese patients in primary care? A systematic review, Health Technology Assessment 2012; Vol. 16: No. 5.
Brasil. Ministério da Saúde. Secretaria de Ciência, Tecnologia e Insumos Estratégicos. Departamento de Ciência e Tecnologia. Diretrizes metodológicas: estudos de avaliação econômica de tecnologias em saúde.
Brasília, 2009. 150 p. (Série A. Normas e Manuais Técnicos).
Warren E, Brennan A, Akehurst R. Cost-Effectiveness of Sibutramine in the Treatment of Obesity. MedDecisMaking, 2004, 24-9.
World Health Organization (WHO). Cost-effectiveness thresholds. 2012. Disponível em: <http://www.who.int/choice/costs/CER_thresholds/en/>. Acesso em: 1 mar 2014.