A lifetime Markov model for the economic evaluation of chronic obstructive pulmonary disease

Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT

Background

Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear.

Objectives

The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective.

Design

This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation.

Setting and participants

Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458).

Intervention

The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity.

Main outcome measures

The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed.

Results

The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236).

Conclusions

There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective.

Limitations

Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence.

Future work

Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence.

Trial registration

This trial is registered as ISRCTN47776579.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information.

A cost-effectiveness analysis of national smoking cessation services among chronic obstructive pulmonary disease patients in Thailand

AIMS

Thailand's national smoking cessation services (FAH-SAI clinics) were founded in 2010. A cost-effectiveness analysis (CEA) is needed to inform policymakers of the allocation and prioritization of the limited budget to maximize the value for money of reimbursing these services. Chronic obstructive pulmonary disease (COPD) patients would benefit from smoking cessation services. Therefore, this study aimed to assess the cost-effectiveness of these multidisciplinary services compared to the usual care among COPD patients in Thailand from a societal perspective.

METHODS

We conducted a CEA from a societal perspective using a Markov model to simulate lifetime costs and quality-adjusted life years (QALYs) gained by each smoking cessation intervention over the patient's lifetime. We derived the effectiveness of the smoking cessation services from a multicenter, longitudinal study of smoking cessation services in Thailand and estimated the natural quit rate, transition probabilities, health utility, and cost data from the published literature. Costs and outcomes were discounted at 3%. Sensitivity analyses were performed.

RESULTS

Compared to the usual care, FAH-SAI clinics were associated with higher costs (4,207 THB (US$133)) and improved QALYs (0.11), with an incremental cost-effectiveness ratio of 37,675 THB/QALY (US$1,187/QALY). The effectiveness of FAH-SAI clinics was a key driver of the cost-effectiveness results. At the willingness-to-pay (WTP) threshold of 160,000 THB (US$5,042) per QALY gained, the probability of being cost-effective was 96.5%.

CONCLUSIONS

FAH-SAI clinics were cost-effective under Thailand's WTP threshold. Our results could inform policymakers in allocating resources to support smoking cessation services for COPD patients in Thailand.

Costs of Treatment of Severe COPD Exacerbation in Serbia

The main objective of this investigation was to determine and summarize the economic burden of severe COPD exacerbations that required hospitalization and the difference in the costs of treatment between patients with frequent (at least two exacerbations in one year) and infrequent exacerbation.

Our results suggested that significantly more resources had to be spent to treat patients with at least two hospitalizations during the study related to the use of medications primarily affecting the respiratory system (corticosteroids, p = 0.013, theophylline, p = 0.007) and total hospital stay (31336.68 ± 19140 RSD/517.53 ± 316.1 EUR versus 23650.15 ± 14956.0 RSD/390.59 ± 247 EUR, p=0.002) compared to patients who stayed in a semi-intensive care unit (12875.35 ± 20742.54 RSD versus 4310.62 ± 9779.78 RSD/ 212.64 ± 342.57 EUR versus 71.19 ± 161.51 EUR, p=0.006). Based on the total number of days in the hospital, the costs of the drugs, the materials used and services provided, patients from the frequent exacerbation group had significantly higher costs (80034.1 ± 36823.7 RSD/1321.78 ± 608.15 EUR versus 69425.5 ± 34083.1 RSD/1146.58 ± 562.89 EUR) comparedthan patients in the infrequent exacerbation group (p=0.039).

Our results indicate that significantly more funds will be spent treating the deterioration of patients who stay longer in the hospital or in the semi-intensive care unit. Their condition will require a significantly greater use of drugs that are primarily used to treat the respiratory system and, therefore, will utiliseutilize significantly more resources.

Predicting the outcomes and costs for a cohort of 426 patients with Chronic Obstructive Pulmonary Disease (COPD) in Bulgaria through a Markov model

The aim was to estimate the economic burden, as well as rate of progression of COPD for a cohort of 426 patients for a 10-year period. A total of 426 patients from 19 regions with Chronic Obstructive Pulmonary Disease were enrolled in a representative, ambispective, national study for Bulgaria. Patients were recorded on disease stage, occupation, smoking habits and medication. Cost of treatment was calculated and a 10-year one-way Markov model was used by employing transition probabilities and quality of life data from available literature. Costs and outcomes were recorded and a cost-effectiveness acceptability curve (CEAC) was established.

Out of all patients included in the study 288 were non-smokers with a mortality percentage after 10 years of 42.7%. Smokers showed faster transition rate with 139 of them transitioning to more severe states and mortality was 54.6%. The incremental cost-effectiveness ratio (ICER) was 863.75 BGN. Patients who smoked had a lower quality of life – cumulatively for the 10-year period QALY = 623.51 for smokers vs. 1557.51 for non-smokers, but also lower costs for treatment (538 007.52 BGN vs. 1 344 757.95 BGN) accounted by the high transition rate and mortality amongst that group. Relatively few non-smokers transitioned from a less severe to a more severe state (6%), while most of the very severe stage patients experienced a lethal outcome within 10 years (81%).

Despite the higher costs associated with the disease, the Quality of Life and lower transition probability would enable patients to live a normal life. The ICER was well below the WHO threshold.

A Novel Method for Analysing Frequent Observations from Questionnaires in Order to Model Patient-Reported Outcomes: Application to EXACT® Daily Diary Data from COPD Patients

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease with approximately 174 million cases worldwide. Electronic questionnaires are increasingly used for collecting patient-reported-outcome (PRO) data about disease symptoms. Our aim was to leverage PRO data, collected to record COPD disease symptoms, in a general modelling framework to enable interpretation of PRO observations in relation to disease progression and potential to predict exacerbations. The data were collected daily over a year, in a prospective, observational study. The e-questionnaire, the EXAcerbations of COPD Tool (EXACT®) included 14 items (i.e. questions) with 4 or 5 ordered categorical response options. An item response theory (IRT) model was used to relate the responses from each item to the underlying latent variable (which we refer to as disease severity), and on each item level, Markov models (MM) with 4 or 5 categories were applied to describe the dependence between consecutive observations. Minimal continuous time MMs were used and parameterised using ordinary differential equations. One hundred twenty-seven COPD patients were included (median age 67 years, 54% male, 39% current smokers), providing approximately 40,000 observations per EXACT® item. The final model suggested that, with time, patients more often reported the same scores as the previous day, i.e. the scores were more stable. The modelled COPD disease severity change over time varied markedly between subjects, but was small in the typical individual. This is the first IRT model with Markovian properties; our analysis proved them necessary for predicting symptom-defined exacerbations.

Development and Validation of the Evaluation Platform in COPD (EPIC): A Population-Based Outcomes Model of COPD for Canada

BACKGROUND

We report the development, validation, and implementation of an open-source population-based outcomes model of chronic obstructive pulmonary disease (COPD) for Canada.

METHODS

Evaluation Platform in COPD (EPIC) is a discrete-event simulation model of Canadians 40 years of age or older. Three core features of EPIC are its open-population design (incorporating projections of future population growth, aging, and smoking trends), its incorporation of heterogeneity in lung function decline and burden of exacerbations, and its modeling of the natural history of COPD from inception. Multiple original data analyses, as well as values reported in the literature, were used to populate the model. Extensive face validity and internal and external validity evaluations were performed.

RESULTS

The model was internally validated on demographic projections, mortality rates, lung function trajectories, COPD exacerbations, costs and health state utility values, and stability of COPD prevalence over time within strata of risk factors. In external validation, it moderately overestimated the rate of overall exacerbations in 2 independent trials but generated consistent estimates of rate of severe exacerbations and mortality.

LIMITATIONS

In its current version, EPIC does not consider uncertainty in the evidence. Several components such as additional (e.g., environmental and occupational) risk factors, treatment, symptoms, and comorbidity will have to be added in future iterations. Predictive validity of EPIC needs to be examined prospectively against future empirical studies.

CONCLUSIONS

EPIC is the first multipurpose, open-source, outcome- and policy-focused model of COPD for Canada. Platforms of this type have the capacity to be iteratively updated to incorporate the latest evidence and to project the outcomes of many different scenarios within a consistent framework.

An attempt at modeling COPD epidemiological trends in France

Background

Anticipating the future burden of chronic obstructive pulmonary disease (COPD) is required to develop adequate public health policies.

Methods

A dynamic population model was built to estimate COPD prevalence by 2025 using data collected during the most recent large general population study on COPD prevalence in France (2005) as baseline values. Sensitivity analyses were performed to test the effect of variations in key input variables.

Results

The model predicted a steady increase in crude COPD prevalence among subjects aged≥45 years from 2005 (prevalence estimate: 84.51‰) to 2025 (projected prevalence: 95.76‰, + 0.56‰/yr). There was a 4-fold increase in the prevalence of GOLD grade 3–4 cases, a 23% relative increase in women and a 21% relative increase in subjects ≥75 years. In sensitivity analyses, these temporal trends were robust. Factors associated with > 5% relative variations in projected 2025 prevalence estimates were baseline prevalence and severity distribution, incidence in women and severity of incident cases, transition rates between severity grades, and mortality.

Conclusions

Projections of future COPD epidemiology consistently predict an increase in the prevalence of moderate-to-very severe COPD, especially due to increases among women and subjects aged ≥75 years. Developing robust prediction models requires collecting reliable data on current COPD epidemiology.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0827-7) contains supplementary material, which is available to authorized users.

External Validation of Health Economic Decision Models for Chronic Obstructive Pulmonary Disease (COPD): Report of the Third COPD Modeling Meeting

OBJECTIVES

To validate outcomes of presently available chronic obstructive pulmonary disease (COPD) cost-effectiveness models against results of two large COPD trials-the 3-year TOwards a Revolution in COPD Health (TORCH) trial and the 4-year Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT) trial.

METHODS

Participating COPD modeling groups simulated the outcomes for the placebo-treated groups of the TORCH and UPLIFT trials using baseline characteristics of the trial populations as input. Groups then simulated treatment effectiveness by using relative reductions in annual decline in lung function and exacerbation frequency observed in the most intensively treated group compared with placebo as input for the models. Main outcomes were (change in) total/severe exacerbations and mortality. Furthermore, the absolute differences in total exacerbations and quality-adjusted life-years (QALYs) were used to approximate the cost per exacerbation avoided and the cost per QALY gained.

RESULT

Of the six participating models, three models reported higher total exacerbation rates than observed in the TORCH trial (1.13/patient-year) (models: 1.22-1.48). Four models reported higher rates than observed in the UPLIFT trial (0.85/patient-year) (models: 1.13-1.52). Two models reported higher mortality rates than in the TORCH trial (15.2%) (models: 20.0% and 30.6%) and the UPLIFT trial (16.3%) (models: 24.8% and 36.0%), whereas one model reported lower rates (9.8% and 12.1%, respectively). Simulation of treatment effectiveness showed that the absolute reduction in total exacerbations, the gain in QALYs, and the cost-effectiveness ratios did not differ from the trials, except for one model.

CONCLUSIONS

Although most of the participating COPD cost-effectiveness models reported higher total exacerbation rates than observed in the trials, estimates of the absolute treatment effect and cost-effectiveness ratios do not seem different from the trials in most models.

A Systematic Review of Health Economics Simulation Models of Chronic Obstructive Pulmonary Disease

BACKGROUND

Many decision-analytic models with varying structures have been developed to inform resource allocation in chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To review COPD models for their adherence to the best practice modeling recommendations and their assumptions regarding important aspects of the natural history of COPD.

METHODS

A systematic search of English articles reporting on the development or application of a decision-analytic model in COPD was performed in MEDLINE, Embase, and citations within reviewed articles. Studies were summarized and evaluated on the basis of their adherence to the Consolidated Health Economic Evaluation Reporting Standards. They were also evaluated for the underlying assumptions about disease progression, heterogeneity, comorbidity, and treatment effects.

RESULTS

Forty-nine models of COPD were included. Decision trees and Markov models were the most popular techniques (43 studies). Quality of reporting and adherence to the guidelines were generally high, especially in more recent publications. Disease progression was modeled through clinical staging in most studies. Although most studies (n = 43) had incorporated some aspects of COPD heterogeneity, only 8 reported the results across subgroups. Only 2 evaluations explicitly considered the impact of comorbidities. Treatment effect had been mostly modeled (20) as both reduction in exacerbation rate and improvement in lung function.

CONCLUSIONS

Many COPD models have been developed, generally with similar structural elements. COPD is highly heterogeneous, and comorbid conditions play an important role in its burden. These important aspects, however, have not been adequately addressed in most of the published models.

Patient Heterogeneity in Health Economic Decision Models for Chronic Obstructive Pulmonary Disease: Are Current Models Suitable to Evaluate Personalized Medicine?

OBJECTIVES

To assess how suitable current chronic obstructive pulmonary disease (COPD) cost-effectiveness models are to evaluate personalized treatment options for COPD by exploring the type of heterogeneity included in current models and by validating outcomes for subgroups of patients.

METHODS

A consortium of COPD modeling groups completed three tasks. First, they reported all patient characteristics included in the model and provided the level of detail in which the input parameters were specified. Second, groups simulated disease progression, mortality, quality-adjusted life-years (QALYs), and costs for hypothetical subgroups of patients that differed in terms of sex, age, smoking status, and lung function (forced expiratory volume in 1 second [FEV₁] % predicted). Finally, model outcomes for exacerbations and mortality for subgroups of patients were validated against published subgroup results of two large COPD trials.

RESULTS

Nine COPD modeling groups participated. Most models included sex (seven), age (nine), smoking status (six), and FEV₁% predicted (nine), mainly to specify disease progression and mortality. Trial results showed higher exacerbation rates for women (found in one model), higher mortality rates for men (two models), lower mortality for younger patients (four models), and higher exacerbation and mortality rates in patients with severe COPD (four models).

CONCLUSIONS

Most currently available COPD cost-effectiveness models are able to evaluate the cost-effectiveness of personalized treatment on the basis of sex, age, smoking, and FEV₁% predicted. Treatment in COPD is, however, more likely to be personalized on the basis of clinical parameters. Two models include several clinical patient characteristics and are therefore most suitable to evaluate personalized treatment, although some important clinical parameters are still missing.

Do Model-Based Studies in Chronic Obstructive Pulmonary Disease Measure Correct Values of Utility? A Meta-Analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive chronic disease that has considerable impact on utility-based health-related quality of life. Utility is a key input of many decision analytic models used for economic evaluations.

OBJECTIVE

To systematically review COPD-related utilities and to compare these with alternative values used in decision models.

METHODS

The literature review comprised studies that generated utilities for COPD-related stages based on EuroQol five-dimensional questionnaire surveys of patients and of decision models of COPD progression that have been used for economic evaluations. The utility values used in modeling studies and those from the meta-analysis of actual patient-level studies were compared and differences quantified.

RESULTS

Twenty decision modeling studies that used utility value as an input parameter were found. Within the same span of publication period, 13 studies involving patient-level utility data were identified and included in the meta-analysis. The estimated mean utility values ranged from 0.806 (95% confidence interval [CI] 0.747-0.866) for stage I to 0.616 (95% CI 0.556-0.676) for stage IV. The utility scores for comparable stages in modeling studies were different (significant difference 0.045 [95% CI 0.041-0.052] for stage III). Modeling studies consistently used higher utility values than the average reported patient-level data.

CONCLUSIONS

COPD decision analytic models are based on a limited range of utility values that are systematically different from average values estimated using a meta-analysis. A more systematic approach in the application of utility measures in economic evaluation is required to appropriately reflect current literature.

Choosing an epidemiological model structure for the economic evaluation of non-communicable disease public health interventions

Non-communicable diseases are the leading global causes of mortality and morbidity. Growing pressures on health services and on social care have led to increasing calls for a greater emphasis to be placed on prevention. In order for decisionmakers to make informed judgements about how to best spend finite public health resources, they must be able to quantify the anticipated costs, benefits, and opportunity costs of each prevention option available. This review presents a taxonomy of epidemiological model structures and applies it to the economic evaluation of public health interventions for non-communicable diseases. Through a novel discussion of the pros and cons of model structures and examples of their application to public health interventions, it suggests that individual-level models may be better than population-level models for estimating the effects of population heterogeneity. Furthermore, model structures allowing for interactions between populations, their environment, and time are often better suited to complex multifaceted interventions. Other influences on the choice of model structure include time and available resources, and the availability and relevance of previously developed models. This review will help guide modelers in the emerging field of public health economic modeling of non-communicable diseases.

Cost Effectiveness of Free Access to Smoking Cessation Treatment in France Considering the Economic Burden of Smoking-Related Diseases

CONTEXT

In France more than 70,000 deaths from diseases related to smoking are recorded each year, and since 2005 prevalence of tobacco has increased. Providing free access to smoking cessation treatment would reduce this burden. The aim of our study was to estimate the incremental cost-effectiveness ratios (ICER) of providing free access to cessation treatment taking into account the cost offsets associated with the reduction of the three main diseases related to smoking: lung cancer, chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD). To measure the financial impact of such a measure we also conducted a probabilistic budget impact analysis.

METHODS AND FINDINGS

We performed a cost-effectiveness analysis using a Markov state-transition model that compared free access to cessation treatment to the existing coverage of €50 provided by the French statutory health insurance, taking into account the cost offsets among current French smokers aged 15-75 years. Our results were expressed by the incremental cost-effectiveness ratio in 2009 Euros per life year gained (LYG) at the lifetime horizon. We estimated a base case scenario and carried out a Monte Carlo sensitivity analysis to account for uncertainty. Assuming a participation rate of 7.3%, the ICER value for free access to cessation treatment was €3,868 per LYG in the base case. The variation of parameters provided a range of ICER values from -€736 to €15,715 per LYG. In 99% of cases, the ICER for full coverage was lower than €11,187 per LYG. The probabilistic budget impact analysis showed that the potential cost saving for lung cancer, COPD and CVD ranges from €15 million to €215 million at the five-year horizon for an initial cessation treatment cost of €125 million to €421 million.

CONCLUSION

The results suggest that providing medical support to smokers in their attempts to quit is very cost-effective and may even result in cost savings.

Mathematical Modeling in Tobacco Control Research: Initial Results From a Systematic Review

OBJECTIVES

The US Food and Drug Administration has expressed interest in using mathematical models to evaluate potential tobacco policies. The goal of this systematic review was to synthesize data from tobacco control studies that employ mathematical models.

METHODS

We searched five electronic databases on July 1, 2013 to identify published studies that used a mathematical model to project a tobacco-related outcome and developed a data extraction form based on the ISPOR-SMDM Modeling Good Research Practices. We developed an organizational framework to categorize these studies and identify models employed across multiple papers. We synthesized results qualitatively, providing a descriptive synthesis of included studies.

RESULTS

The 263 studies in this review were heterogeneous with regard to their methodologies and aims. We used the organizational framework to categorize each study according to its objective and map the objective to a model outcome. We identified two types of study objectives (trend and policy/intervention) and three types of model outcomes (change in tobacco use behavior, change in tobacco-related morbidity or mortality, and economic impact). Eighteen models were used across 118 studies.

CONCLUSIONS

This paper extends conventional systematic review methods to characterize a body of literature on mathematical modeling in tobacco control. The findings of this synthesis can inform the development of new models and the improvement of existing models, strengthening the ability of researchers to accurately project future tobacco-related trends and evaluate potential tobacco control policies and interventions. These findings can also help decision-makers to identify and become oriented with models relevant to their work.

Utilities for asthma and COPD according to category of severity: a comprehensive literature review

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) are incurable diseases that impact quality-of-life.

OBJECTIVE

To summarize original research articles that measured or utilized preference-based utilities or disutilities according to disease severity.

METHODS

Medline and Embase were searched from inception until the end of November 2014. Two reviewers independently searched the literature with differences settled through discussion. Data extracted included utility scores as determined in original research categorized according to disease severity as well as disutilities associated with exacerbations or comorbidities. Data were tabulated and analyzed descriptively.

RESULTS

In total, 862 articles were identified, 790 were rejected, and 69 analyzed. There were 44 dealing with COPD and 25 with asthma. Average utilities determined by research were 0.828 ± 0.062, 0.765 ± 0.090, 0.711 ± 0.120, and 0.607 ± 0.120 for mild, moderate, severe, and very severe COPD, respectively. Utilities used in economic analyses were 0.866 ± 0.038, 0.770 ± 0.024, 0.739 ± 0.045, and 0.596 ± 0.075, respectively. Disutilities (annual) ranged from 0.002-0.378; major and minor exacerbations had respective disutilities of 0.287 and 0.108. For asthma patients, utilities were for 0.86 ± 0.32, 0.83 ± 0.065, and 0.74 ± 0.029, for mild, moderate, and severe disease, respectively.

CONCLUSIONS

Utilities have been summarized according to severity category of asthma and COPD. These values should be useful for researchers undertaking economic analyses of these diseases.

Quality-adjusted life-years gain and health status in patients with OSAS after one year of continuous positive airway pressure use

STUDY OBJECTIVES

To estimate the health utility score and quality-adjusted life-years (QALY) index of obstructive sleep apnea syndrome (OSAS) in patients over 1 y of continuous positive airway pressure (CPAP) treatment.

DESIGN

Longitudinal interventional study.

SETTING

The study was carried out in Sao Paulo Sleep Institute, Brazil.

PATIENTS AND PARTICIPANTS

Ninety-five patients with OSAS and with apnea-hypopnea index (AHI) > 20 of either sex, body mass index < 40 kg/m(2), and no previous contact with CPAP were included.

INTERVENTIONS

The participants underwent baseline and titration polysomnographies, clinical evaluation, and ambulatory blood pressure (BP) measurement, completed Short-Form 6 Dimension Health Survey (SF-6D) and Epworth Sleepiness Scale (ESS) questionnaires, and implementation of CPAP. The patients were followed for 1 y.

MEASUREMENTS AND RESULTS

The mean AHI and age were 57.6 ± 29.2 events/h and 53.3 ± 9.3 y, respectively. One year of CPAP treatment increased the health utility score from 0.611 ± 0.112 to 0.710 ± 0.121 (P < 0.01). Therefore, CPAP resulted in a mean gain of 0.092 QALY/patient. The improvements in utility scores were associated with decreases in the ESS after 1 mo, in systolic BP after 1 y, and in diastolic BP at 6 mo. BP normalization group (≤ 130/85 mmHg) showed higher QALY than that of the non-normalization group (0.10 ± 0.09 versus 0.05 ± 0.10; P = 0.03). One-year ESS score (P = 0.03), diastolic BP reduction P = 0.01) and baseline utility scores (P < 0.01) were significantly associated with QALY gain.

CONCLUSION

This study showed a significant QALY/patient gain after 1 y of regular CPAP use. In addition, BP normalization was associated with higher QALY gain. Thus, utility studies can provide more complete analyses of the total benefits of CPAP treatment in patients with OSAS and should be encouraged.

A retrospective study of the impact of a telephone alert service (Healthy Outlook) on hospital admissions for patients with chronic obstructive pulmonary disease

BACKGROUND

Healthy Outlook is a service delivered by the UK Met Office directly to patients with chronic obstructive pulmonary disease (COPD) that has been in place since 2006. Its objective is to reduce the severity and length of COPD exacerbations, hence improving the quality of life and life expectancy.

AIMS

To assess the effect of the Healthy Outlook service on hospital admission rates of all general practitioners that have used the service.

METHODS

Control practices were selected for each of the 661 participating practices. The number of hospital admissions for each practice was extracted from the Hospital Episode Statistics database. The differences in admission rates per practice between the first year of use of the Healthy Outlook service and the previous year were compared by paired t-test analyses.

RESULTS

For admissions with a primary diagnosis of COPD, the difference between participating and control practices was -0.8% (95% confidence interval (CI)=-1.8 to 0.2%; P=0.13). For admissions with a primary or co-morbid diagnosis of COPD, the difference was -2.3% (95% CI=-4.2 to -0.4%; P=0.02).

CONCLUSIONS

Participation in the Healthy Outlook service reduces hospital admission rates for patients coded on discharge with COPD (including co-morbid).

Cost-effectiveness of endobronchial valve therapy for severe emphysema: a model-based projection based on the VENT study

BACKGROUND

Endobronchial valve (EBV) therapy is an innovative treatment that has been shown to be safe and effective in selected subgroups of patients with severe emphysema.

OBJECTIVES

The objective of our study was to assess the cost-effectiveness of EBV therapy compared to the medical management of patients with high heterogeneity, complete fissures and lobar exclusion in the context of the German health-care system.

METHODS

Clinical data from a subset of VENT (Endobronchial Valve for Emphysema Palliation Trial) provided information about clinical events, health-related quality of life, and disease staging for 12 months. This information was subsequently used to project long-term disease progression, mortality, and health resource utilization. We computed the 5- and 10-year incremental cost-effectiveness ratio (ICER) in euros per quality-adjusted life year (QALY). Costs and effects were discounted at 3% per year.

RESULTS

EBV therapy led to clinically meaningful disease restaging at 12 months (37.8% of the cohort improved staging, compared to 0% in the controls). Over 5 years, EBV therapy was projected to increase survival from 66.4 to 70.7%, and to add 0.22 QALYs. Costs were estimated to increase by EUR 10,299, resulting in an ICER of EUR 46,322 per QALY. Over 10 years, 0.41 QALYs were gained at an additional cost of EUR 10,425, yielding an ICER of EUR 25,142 per QALY.

CONCLUSIONS

Our model-based analysis suggests that EBV therapy leads to clinically meaningful changes in disease staging and progression when compared to medical management, with resulting gains in unadjusted and quality-adjusted life expectancy. Our results indicate that EBV therapy is cost-effective in the German health-care system.

Cost-effectiveness models for chronic obstructive pulmonary disease: cross-model comparison of hypothetical treatment scenarios

OBJECTIVES

To compare different chronic obstructive pulmonary disease (COPD) cost-effectiveness models with respect to structure and input parameters and to cross-validate the models by running the same hypothetical treatment scenarios.

METHODS

COPD modeling groups simulated four hypothetical interventions with their model and compared the results with a reference scenario of no intervention. The four interventions modeled assumed 1) 20% reduction in decline in lung function, 2) 25% reduction in exacerbation frequency, 3) 10% reduction in all-cause mortality, and 4) all these effects combined. The interventions were simulated for a 5-year and lifetime horizon with standardization, if possible, for sex, age, COPD severity, smoking status, exacerbation frequencies, mortality due to other causes, utilities, costs, and discount rates. Furthermore, uncertainty around the outcomes of intervention four was compared.

RESULTS

Seven out of nine contacted COPD modeling groups agreed to participate. The 5-year incremental cost-effectiveness ratios (ICERs) for the most comprehensive intervention, intervention four, was €17,000/quality-adjusted life-year (QALY) for two models, €25,000 to €28,000/QALY for three models, and €47,000/QALY for the remaining two models. Differences in the ICERs could mainly be explained by differences in input values for disease progression, exacerbation-related mortality, and all-cause mortality, with high input values resulting in low ICERs and vice versa. Lifetime results were mainly affected by the input values for mortality. The probability of intervention four to be cost-effective at a willingness-to-pay value of €50,000/QALY was 90% to 100% for five models and about 70% and 50% for the other two models, respectively.

CONCLUSIONS

Mortality was the most important factor determining the differences in cost-effectiveness outcomes between models.

Improving inhaler adherence in patients with chronic obstructive pulmonary disease: a cost-effectiveness analysis

BACKGROUND

The PHARMACOP-intervention significantly improved medication adherence and inhalation technique for patients with COPD compared with usual care. This study aimed to evaluate its cost-effectiveness.

METHODS

An economic analysis was performed from the Belgian healthcare payer's perspective. A Markov model was constructed in which a representative group of patients with COPD (mean age of 70 years, 66% male, 43% current smokers and mean Forced Expiratory Volume in 1 second of % predicted of 50), was followed for either receiving the 3-month PHARMACOP-intervention or usual care. Three types of costs were calculated: intervention costs, medication costs and exacerbation costs. Outcome measures included the number of hospital-treated exacerbations, cost per prevented hospital-treated exacerbation and cost per Quality Adjusted Life-Year. Follow-up was 1 year in the basecase analysis. Sensitivity and scenario analyses (including long-term follow-up) were performed to assess uncertainty.

RESULTS

In the basecase analysis, the average overall costs per patient for the PHARMACOP-intervention and usual care were €2,221 and €2,448, respectively within the 1-year time horizon. This reflects cost savings of €227 for the PHARMACOP-intervention. The PHARMACOP-intervention resulted in the prevention of 0.07 hospital-treated exacerbations per patient (0.177 for PHARMACOP versus 0.244 for usual care). Results showed robust cost-savings in various sensitivity analyses.

CONCLUSIONS

Optimization of current pharmacotherapy (e.g. close monitoring of inhalation technique and medication adherence) has been shown to be cost-saving and should be considered before adding new therapies.

Improving clinical reality in chronic obstructive pulmonary disease economic modelling : development and validation of a micro-simulation approach

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible disease responsible for the deaths of 3 million people worldwide in 2005, and predicted to be the third leading cause of death worldwide by 2030. Many COPD models developed to date have followed a Markov structure, in which patients or populations can move between defined health states over successive time periods or cycles. In COPD, health states are typically based on disease severity defined solely by lung function, as described by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. These current modelling methods may restrict the ability to reflect the disease progression/clinical pathway or clinical practice.

OBJECTIVES

Given these limitations in previous COPD models, the authors aimed to develop a more flexible model that could improve on the description of the clinical disease pathway. The overall objective of this model was to inform the development of policies, guidelines or cost-effectiveness analyses. A second objective was to validate the model in relation to existing epidemiology studies of COPD.

METHODS

A patient simulation model was developed in Microsoft Excel™. The predictability of the model was tested by populating it with data from natural history of disease studies as well as with clinical trial data. Each patient moves through the model with demographic characteristics randomly generated from a set distribution. These characteristics determine the risk of clinical events occurring in the model.

RESULTS

The validation with these studies found the model to have generally good predictive ability, yielding in this way a good degree of external validity.

CONCLUSIONS

The micro-simulation model is a flexible approach for modelling COPD that allows consideration of complex COPD treatment pathways. The model was found to be generally robust in terms of predicting clinical outcomes of published studies when tested against other studies. It has significant potential as a tool for supporting future COPD treatment positioning decisions as well as to inform the development of policies, guidelines or cost-effectiveness analyses.