Broadening the Perspective of Cost-Effectiveness Modeling in Chronic Obstructive Pulmonary Disease: A New Patient-Level Simulation Model Suitable to Evaluate Stratified Medicine

Abstract

To develop a health economic model that included a great diversity of patient characteristics and outcomes for chronic obstructive pulmonary disease (COPD), which can be used to inform decisions about stratified medicine in COPD. Methods: The choice of patient characteristics and outcomes to include in the model was based on 3 literature reviews on multidimensional prognostic COPD indices, COPD phenotypes, and treatment effects in subgroups. A conceptual model was constructed including 14 patient characteristics, 7 intermediate outcomes (lung function, physical activity, exercise capacity, symptoms, disease-specific quality of life, exacerbations, and pneumonias), and 3 final outcomes (mortality, quality-adjusted life-years [QALYs], and costs). Regression equations describing the statistical associations between the patient characteristics and intermediate and final outcomes were estimated using the longitudinal data of 5 large COPD trials (19,378 patients). A patientlevel simulation model was developed in which individual patients from the baseline population of the 5 trials are sampled and their outcomes over lifetime are predicted based on the regression equations. Results: The base-case analysis (single-arm simulation representing treatment with tiotropium) showed that patients had a mean lung function decline of 43 mL/year, 0.62 exacerbations/year, a worsening of their physical activity and quality of life with 1.48 and 1.10 points/year, a life expectancy of 11.2 years, 7.25 QALYs, and total lifetime costs of £24,891. Results for a selection of treatment scenarios and subgroups were shown to demonstrate the potential of the model. Conclusions: We developed a unique patient-level simulation model that can be used to evaluate COPD treatment options for a variety of subgroups.

<p>Long-term cost-effectiveness of the fixed-dose combination of tiotropium plus olodaterol based on the DYNAGITO trial results</p>

“…Given the continuously increasing health care expenditures, especially for medication, cost-effectiveness (CE) information becomes increasingly important to guide reimbursement decisions and clinical guideline development. Therefore, the aim of this study was to estimate the long-term CE of tiotropium + olodaterol vs tiotropium monotherapy in a French health care setting by applying the reduction in exacerbations observed in the DYNAGITO trial in a recently developed COPD CE model 7…”

How to Address Uncertainty in Health Economic Discrete-Event Simulation Models: An Illustration for Chronic Obstructive Pulmonary Disease

“…A full description of the HE COPD model was published in Hoogendoorn et al 34 The main objective of the model was to simulate major COPD-related events over a lifetime and to calculate HE outcomes such as total costs and quality-adjusted life years (QALYs) for a population of COPD patients. The backbone of the model is a set of regression equations describing the associations between patient and disease characteristics and different COPD-related events, as well as intermediate and final COPD outcomes.…”

“…The way remaining life expectancy was adjusted after events occur in the COPD model is used here for illustrative purposes. As explained in Hoogendoorn et al, 34 a Weibull distribution was used to simulate time to death (at baseline) for patients in the COPD model. The parameters (shape and scale) of the Weibull distribution function were estimated using the equation shown in Table 1 , which resulted in the patient’s life expectancy predicted at baseline.…”

“…We describe the solutions to several issues faced during the development of a new DES model for chronic obstructive pulmonary disease (COPD) and present the results of hypothetical cost-effectiveness analyses to illustrate the impact of each type of uncertainty on the model outcomes. 34 These are common issues that can be encountered in other DES models. Thus, the methods explained in this article could be applied to other DES models as well.…”

<p>Modelling the Cost-Effectiveness of Indacaterol/Glycopyrronium versus Salmeterol/Fluticasone Using a Novel Markov Exacerbation-Based Approach</p>

“…[16][17][18][19][20] Such models include a recent patient-level simulation model that included 14 patient characterstics, seven intermediate outcomes (eg lung function, exacerbations, and pnemonias) and three final outcomes (mortality, qualityadjusted life years [QALYs] and costs), which allowed for evaluation of the effect of treatment for various subgroups of COPD patients. 21 Indacaterol/glycopyrronium (IND/GLY) was the first LABA/LAMA combination to be approved for the treatment of COPD and consequently, its cost-effectiveness has been studied extensively, [16][17][18][19]22,23 including via microsimulation modelling. 18,20 In the microsimulation model, 20 IND/GLY was shown to be cost-effective compared with the LABA/ inhaled corticosteroid (ICS) combination salmeterol/fluticasone (SFC) in patients at risk of exacerbations.…”