Rudolf T. Hoogenveen

Lifetime medical costs of obesity: Prevention no cure for increasing health expenditure

Background Obesity is a major cause of morbidity and mortality and is associated with high medical expenditures. It has been suggested that obesity prevention could result in cost savings. The objective of this study was to estimate the annual and lifetime medical costs attributable to obesity, to compare those to similar costs attributable to smoking, and to discuss the implications for prevention. Methods and Findings With a simulation model, lifetime health-care costs were estimated for a cohort of obese people aged 20 y at baseline. To assess the impact of obesity, comparisons were made with similar cohorts of smokers and “healthy-living” persons (defined as nonsmokers with a body mass index between 18.5 and 25). Except for relative risk values, all input parameters of the simulation model were based on data from The Netherlands. In sensitivity analyses the effects of epidemiologic parameters and cost definitions were assessed. Until age 56 y, annual health expenditure was highest for obese people. At older ages, smokers incurred higher costs. Because of differences in life expectancy, however, lifetime health expenditure was highest among healthy-living people and lowest for smokers. Obese individuals held an intermediate position. Alternative values of epidemiologic parameters and cost definitions did not alter these conclusions. Conclusions Although effective obesity prevention leads to a decrease in costs of obesity-related diseases, this decrease is offset by cost increases due to diseases unrelated to obesity in life-years gained. Obesity prevention may be an important and cost-effective way of improving public health, but it is not a cure for increasing health expenditures.

A dynamic population model of disease progression in COPD

To contribute to evidence-based policy making, a dynamic Dutch population model of chronic obstructive pulmonary disease (COPD) progression was developed. The model projects incidence, prevalence, mortality, progression and costs of diagnosed COPD by the Global Initiative for Chronic Obstructive Lung Disease-severity stage for 2000–2025, taking into account population dynamics and changes in smoking prevalence over time. It was estimated that of all diagnosed COPD patients in 2000, 27% had mild, 55% moderate, 15% severe and 3% very severe COPD. The severity distribution of COPD incidence was computed to be 40% mild, 55% moderate, 4% severe and 0.1% very severe COPD. Disease progression was modelled as decline in forced expiratory voume in one second (FEV1) % predicted depending on sex, age, smoking and FEV1 % pred. The relative mortality risk of a 10-unit decrease in FEV1 % pred was estimated at 1.2. Projections of current practice were compared with projections assuming that each year 25% of all COPD patients receive either minimal smoking cessation counselling or intensive counselling plus bupropion. In the projections of current practice, prevalence rates between 2000–2025 changed from 5.1 to 11 per 1,000 inhabitants for mild, 11 to 14 per 1,000 for moderate, 3.0 to 3.9 per 1,000 for severe and from 0.5 to 1.3 per 1,000 for very severe COPD. Costs per inhabitant increased from \#8364;1.40 to 3.10 for mild, \#8364;6.50 to 9.00 for moderate, \#8364;6.20 to 8.50 for severe and from \#8364;3.40 to 9.40 for very severe COPD (price level 2000). Both smoking cessation scenarios were cost-effective with minimal counselling generating net savings. In conclusion, the chronic obstructive pulmonary disease progression model is a useful instrument to give detailed information about the future burden of chronic obstructive pulmonary disease and to assess the long-term impact of interventions on this burden.

Lifestyle Interventions Are Cost-Effective in People With Different Levels of Diabetes Risk: Results from a modeling study.

OBJECTIVE—In the current study we explore the long-term health benefits and cost-effectiveness of both a community-based lifestyle program for the general population (community intervention) and an intensive lifestyle intervention for obese adults, implemented in a health care setting (health care intervention). RESEARCH DESIGN AND METHODS—Short-term intervention effects on BMI and physical activity were estimated from the international literature. The National Institute for Public Health and the Environment Chronic Diseases Model was used to project lifetime health effects and effects on health care costs for minimum and maximum estimates of short-term intervention effects. Cost-effectiveness was evaluated from a health care perspective and included intervention costs and related and unrelated medical costs. Effects and costs were discounted at 1.5 and 4.0% annually. RESULTS—One new case of diabetes per 20 years was prevented for every 7–30 participants in the health care intervention and for every 300–1,500 adults in the community intervention. Intervention costs needed to prevent one new case of diabetes (per 20 years) were lower for the community intervention (€2,000–9,000) than for the health care intervention (€5,000–21,000). The cost-effectiveness ratios were €3,100–3,900 per quality-adjusted life-year (QALY) for the community intervention and €3,900–5,500 per QALY for the health care intervention. CONCLUSIONS—Health care interventions for high-risk groups and community-based lifestyle interventions targeted to the general population (low risk) are both cost-effective ways of curbing the growing burden of diabetes.

Long-term effectiveness and cost-effectiveness of smoking cessation interventions in patients with COPD

Background The aim of this study was to estimate the long-term (cost-) effectiveness of smoking cessation interventions for patients with chronic obstructive pulmonary disease (COPD). Methods A systematic review was performed of randomised controlled trials on smoking cessation interventions in patients with COPD reporting 12-month biochemical validated abstinence rates. The different interventions were grouped into four categories: usual care, minimal counselling, intensive counselling and intensive counselling + pharmacotherapy (‘pharmacotherapy’). For each category the average 12-month continuous abstinence rate and intervention costs were estimated. A dynamic population model for COPD was used to project the long-term (cost-) effectiveness (25 years) of 1-year implementation of the interventions for 50% of the patients with COPD who smoked compared with usual care. Uncertainty and one-way sensitivity analyses were performed for variations in the calculation of the abstinence rates, the type of projection, intervention costs and discount rates. Results Nine studies were selected. The average 12-month continuous abstinence rates were estimated to be 1.4% for usual care, 2.6% for minimal counselling, 6.0% for intensive counselling and 12.3% for pharmacotherapy. Compared with usual care, the costs per quality-adjusted life year (QALY) gained for minimal counselling, intensive counselling and pharmacotherapy were €16 900, €8200 and €2400, respectively. The results were most sensitive to variations in the estimation of the abstinence rates and discount rates. Conclusion Compared with usual care, intensive counselling and pharmacotherapy resulted in low costs per QALY gained with ratios comparable to results for smoking cessation in the general population. Compared with intensive counselling, pharmacotherapy was cost saving and dominated the other interventions.

Case fatality of COPD exacerbations: A meta-analysis and statistical modelling approach

The aim of our study was to estimate the case fatality of a severe exacerbation from long-term survival data presented in the literature. A literature search identified studies reporting ≥1.5 yr survival after a severe chronic obstructive pulmonary disease (COPD) exacerbation resulting in hospitalisation. The survival curve of each study was divided into a critical and a stable period. Mortality during the stable period was then estimated by extrapolating the survival curve during the stable period back to the time of exacerbation onset. Case fatality was defined as the excess mortality that results from an exacerbation and was calculated as 1 minus the (backwardly) extrapolated survival during the stable period at the time of exacerbation onset. The 95% confidence intervals (CI) of the estimated case fatalities were obtained by bootstrapping. A random effect model was used to combine all estimates into a weighted average with 95% CI. The meta-analysis based on six studies that fulfilled the inclusion criteria resulted in a weighted average case-fatality rate of 15.6% (95% CI 10.9–20.3), ranging from 11.4% to 19.0% for the individual studies. A severe COPD exacerbation requiring hospitalisation not only results in higher mortality risks during hospitalisation, but also in the time-period after discharge and contributes substantially to total COPD mortality.

Dynamic effects of smoking cessation on disease incidence, mortality and quality of life: The role of time since cessation

BackgroundTo support health policy makers in setting priorities, quantifying the potential effects of tobacco control on the burden of disease is useful. However, smoking is related to a variety of diseases and the dynamic effects of smoking cessation on the incidence of these diseases differ. Furthermore, many people who quit smoking relapse, most of them within a relatively short period.MethodsIn this paper, a method is presented for calculating the effects of smoking cessation interventions on disease incidence that allows to deal with relapse and the effect of time since quitting. A simulation model is described that links smoking to the incidence of 14 smoking related diseases. To demonstrate the model, health effects are estimated of two interventions in which part of current smokers in the Netherlands quits smoking.To illustrate the advantages of the model its results are compared with those of two simpler versions of the model. In one version we assumed no relapse after quitting and equal incidence rates for all former smokers. In the second version, incidence rates depend on time since cessation, but we assumed still no relapse after quitting.ResultsNot taking into account time since smoking cessation on disease incidence rates results in biased estimates of the effects of interventions. The immediate public health effects are overestimated, since the health risk of quitters immediately drops to the mean level of all former smokers. However, the long-term public health effects are underestimated since after longer periods of time the effects of past smoking disappear and so surviving quitters start to resemble never smokers. On balance, total health gains of smoking cessation are underestimated if one does not account for the effect of time since cessation on disease incidence rates. Not taking into account relapse of quitters overestimates health gains substantially.ConclusionThe results show that simulation models are sensitive to assumptions made in specifying the model. The model should be specified carefully in accordance with the questions it is supposed to answer. If the aim of the model is to estimate effects of smoking cessation interventions on mortality and morbidity, one should include relapse of quitters and dependency on time since cessation of incidence rates of smoking-related chronic diseases. A drawback of such models is that data requirements are extensive.

Association between lung function and exacerbation frequency in patients with COPD.

Purpose: To quantify the relationship between severity of chronic obstructive pulmonary disease (COPD) as expressed by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage and the annual exacerbation frequency in patients with COPD. Methods: We performed a systematic literature review to identify randomized controlled trials and cohort studies reporting the exacerbation frequency in COPD patients receiving usual care or placebo. Annual frequencies were determined for total exacerbations defined by an increased use of health care (event-based), total exacerbations defined by an increase of symptoms, and severe exacerbations defined by a hospitalization. The association between the mean forced expiratory volume in one second (FEV1)% predicted of study populations and the exacerbation frequencies was estimated using weighted log linear regression with random effects. The regression equations were applied to the mean FEV1% predicted for each GOLD stage to estimate the frequency per stage. Results: Thirty-seven relevant studies were found, with 43 reports of total exacerbation frequency (event-based, n = 19; symptom-based, n = 24) and 14 reports of frequency of severe exacerbations. Annual event-based exacerbation frequencies per GOLD stage were estimated at 0.82 (95% confidence interval 0.46–1.49) for mild, 1.17 (0.93–1.50) for moderate, 1.61 (1.51–1.74) for severe, and 2.10 (1.51–2.94) for very severe COPD. Annual symptom-based frequencies were 1.15 (95% confidence interval 0.67–2.07), 1.44 (1.14–1.87), 1.76 (1.70–1.88), and 2.09 (1.57–2.82), respectively. For severe exacerbations, annual frequencies were 0.11 (95% confidence interval 0.02–0.56), 0.16 (0.07–0.33), 0.22 (0.20–0.23), and 0.28 (0.14–0.63), respectively. Study duration or type of study (cohort versus trial) did not significantly affect the outcomes. Conclusion: This study provides an estimate of the exacerbation frequency per GOLD stage, which can be used for health economic and modeling purposes.

Smoking cessation would substantially reduce the future incidence of pancreatic cancer in the European Union

Objective Since pancreatic cancer is one of the most rapidly fatal cancers, prevention is of paramount importance to reduce the future burden of this disease. We studied the impact of ceasing smoking on the future incidence of pancreatic cancer in the European Union (EU). Methods We developed a computer simulation model, Markov multi-state type, using country-specific published data on population sizes, smoking behaviour, pancreatic cancer incidence and total mortality rates, corresponding relative risks for ex- and current smokers, and estimated probabilities of starting and ceasing smoking (transition rates), with which we refined previously reported preliminary results. We simulated a scenario based on theoretically maximal smoking reduction, a more feasible scenario based on the World Health Organizations ‘Health for All’ target in which smoking prevalence is reduced to 20% in 2015, and scenarios based on reductions in smoking prevalence in 20 steps of 5% (from 0% to 100% reduction) in 2015. Simulations were based on changes in transition rates for smoking behaviour. We estimated the absolute and relative reduction of pancreatic cancer patients in the EU, for each scenario compared to a reference scenario in which the current transition rates remained unchanged, for the period 1994–2015. Results Theoretically, if all smokers would quit instantly, the estimated number of new pancreatic cancer patients up to 2015 in the EU could be reduced by 15% (around 150 000 patients). The more feasible scenario would lead to a reduction of almost 29 500 male and 9500 female patients. These results corresponded to a reduction in smoking prevalence with around 45% and 30% among men and women, respectively, in each EU country. Conclusion Giving up smoking would substantially reduce the future incidence of pancreatic cancer. This emphasizes the importance of prevention in the reduction of the future pancreatic cancer burden.

Food and vessels: the importance of a healthy diet to prevent cardiovascular disease.

Aim We attempted to quantify the burden of cardiovascular disease that can be prevented by broader adherence to recommendations on dietary intake of key nutrients. Methods A computer model capturing the epidemiology of chronic disease and risk factors in the Dutch population was used to simulate differences in the occurrence of cardiovascular disease under various scenarios defined by levels of intake of saturated and trans fatty acids, fruit, vegetables and fish. The following scenarios were compared with the current situation: (i) the whole population adhering to recommendations (optimum scenario); (ii) a moderate improvement and (iii) increased intake of fruit as has been achieved in an actual intervention (‘fruit at work’). Other outcome measures assessed were (differences in) life expectancy and healthy life expectancy for a 40-year-old individual. Results In the optimum scenario, cumulative incidence prevented over a period of 20 years was 240 000 cases for acute myocardial infarction, or 30% of the expected number of cases, 328 000 (16%) for other coronary heart disease and 215 000 (21%) for stroke. For the moderate improvement scenario, the corresponding figures were 119 000 (14%), 163 000 (8%) and 105 000 (10%), respectively. The individual contributions of each of the separate dietary factors were greatest for fish, followed in decreasing order by fruit, vegetables, saturated and trans fatty acids. Only fish and fruit contributed to a decrease in strokes. In the optimum scenario, 1 year was added to the life expectancy of a 40-year-old individual and half a year in the moderate improvement scenario. Conclusion Broader adherence to recommendations for daily intake of fruit, vegetables, fish and fatty acid composition may take away as much as 20-30% of the burden of cardiovascular disease and result in approximately 1 extra life year for a 40-year-old individual. Promotion of a healthy diet should be given more emphasis in the prevention of cardiovascular disease.

Cost-Effectiveness of Lifestyle Modification in Diabetic Patients

OBJECTIVE To explore the potential long-term health and economic consequences of lifestyle interventions for diabetic patients. RESEARCH DESIGN AND METHODS A literature search was performed to identify interventions for diabetic patients in which lifestyle issues were addressed. We selected recent (2003–2008), randomized controlled trials with a minimum follow-up of 12 months. The long-term outcomes for these interventions, if implemented in the Dutch diabetic population, were simulated with a computer-based model. Costs and effects were discounted at, respectively, 4 and 1.5% annually. A lifelong time horizon was applied. Probabilistic sensitivity analyses were performed, taking account of variability in intervention costs and (long-term) treatment effects. RESULTS Seven trials with 147–5,145 participants met our predefined criteria. All interventions improved cardiovascular risk factors at ≥1 year follow-up and were projected to reduce cardiovascular morbidity over lifetime. The interventions resulted in an average gain of 0.01–0.14 quality-adjusted life-years (QALYs) per participant. Health benefits were generally achieved at reasonable costs (≤€50,000/QALY). A self-management education program (X-PERT) and physical activity counseling achieved the best results with ≥0.10 QALYs gained and ≥99% probability to be very cost-effective (≤€20,000/QALY). CONCLUSIONS Implementation of lifestyle interventions would probably yield important health benefits at reasonable costs. However, essential evidence for long-term maintenance of health benefits was limited. Future research should be focused on long-term effectiveness and multiple treatment strategies should be compared to determine incremental costs and benefits of one over the other.