Modeling the efficiency of reaching a target intermediate end point: a case study in type 2 diabetes in the United States

Relationships among self-management, patient perceptions of care, and health economic outcomes for decision-making and clinical practice in type 2 diabetes

OBJECTIVES

Type 2 diabetes (T2D) treatment involves complex interactions between biological, psychological, and behavioral factors of care, requiring multifaceted efforts in clinical practice and disease management to reduce health and economic burdens. We aimed to quantify correlations among these factors and characterize their level of inclusion in economic analyses that are part of informed medical decision-making.

METHODS

A comprehensive, stepwise systematic literature review was performed on published articles dated 1993 to 2008 using medical subject heading and keyword searches in electronic reference libraries. Data were collected using standardized techniques and were analyzed descriptively.

RESULTS

A total of 97 articles fulfilling all inclusion criteria were reviewed, including 16 on economic models (17% of articles). Most studies were retrospective (41 of 97; 42%) and from managed care perspectives (66%). Oral antidiabetic drugs were a central focus, appearing in 83% of studies. Patient behaviors, particularly medication adherence and persistence in real-world settings, are well researched (n=65) and may influence diabetes outcomes, cardiovascular risk, mortality rates, and treatment-specific resource use (e.g., hospitalizations) and costs (<or=$3400 annually per patient). Nevertheless, they are absent from current economic models.

CONCLUSIONS

Strong correlations exist between patient behaviors, perspectives of care, health outcomes, and costs in T2D. Enhancing their inclusion in pharmacoeconomic modeling, notably the influence on clinical effectiveness of variation in self-management between treatments, should ultimately lead to more accurate estimates of comparative cost-effectiveness, and thereby improve value-based resource allocation and patient access to appropriate therapy.

Cost-effectiveness of oral hypoglycaemic agents for the treatment of type 2 diabetes mellitus

Diabetes is a public health problem worldwide. Its treatment includes controlling hyperglycaemia, initially through changes in lifestyle such as diet, exercise and weight loss. UK Prospective Diabetes Study results showed that intensive treatment to achieve glycaemic control in patients with type 2 diabetes reduces the risk of diabetes-related complications. Typically, patients initially receive monotherapy with oral hypoglycaemic agents but usually progress to combination therapy or insulin. In the short term, the cost of achieving glycaemic control can be substantial, particularly when combination therapy is required. However, additional treatment costs of achieving recommended glycaemic control levels are predicted to be at least partially offset in the long term by the reduction of diabetes-related complications and their related management costs.

Pharmacoeconomic analyses using discrete event simulation

To date, decision trees and Markov models have been the most common methods used in pharmacoeconomic evaluations. Both of these techniques lack the flexibility required to appropriately represent clinical reality. In this paper an alternative, more natural, way to model clinical reality--discrete event simulation--is presented and its application is illustrated with a real world example.A discrete event simulation represents the course of disease very naturally, with few restrictions. Neither mutually exclusive branches nor states are required, nor is a fixed cycle. All relevant aspects can be incorporated explicitly and efficiently. Flexibility in handling perspectives and carrying out sensitivity analyses, including structural variations, is incorporated and the entire model can be presented very transparently. The main limitations are imposed by lack of data to fit realistic models. Discrete event simulation, though rarely employed in pharmacoeconomics today, should be strongly considered when carrying out economic evaluations, particularly those aimed at informing policy makers and at estimating the budget impact of a pharmaceutical intervention.