The cost effectiveness of orlistat in a 1-year weight-management programme for treating overweight and obese patients in Sweden : a treatment responder approach

Pharmacoeconomic evaluation of anti-obesity drugs for chronic weight management: a systematic review of literature

Introduction

Pharmacological therapy is recommended as a second-line alternative to reverse obesity. Currently, five anti-obesity drugs (AODs) have been approved by the U.S. Food and Drug Administration (FDA) for chronic weight management. The aim of this paper is to investigate the pharmacoeconomic evaluation of AODs through a systematic review with a special focus on methodological considerations.

Methods

We searched the general and specific databases to identify the primary pharmacoeconomic evaluation of AODs.

Results

A total of 18 full-text articles and three conference abstracts were included in this review. Most of the economic assessments were still about Orlistat. And the observations we could make were consistent with the previous systematic review. A few studies were on the combined therapies (i.e. PHEN/TPM ER and NB ER) compared to different comparators, which could hardly lead to a generalized summary of the cost-effectiveness. Most recently, pharmacoeconomic evidence on the newest GLP 1 RA approved for the indication of obesity or obesity with at least one comorbidity emerged gradually. Modelling-based cost-utility analysis is the major type of assessment method. In the modelling studies, a manageable number of the key health states and the state transitions were structured to capture the disease progression. In particular, the principal structure of the decision model adopted in the three studies on the newly approved drug was nearly the same, which enables more in-depth comparisons and generalizations of the findings.

Conclusion

This study provided an up-to-date overview of the strengths and areas for improvement in the methodological design of the pharmacoeconomic evaluation of the licensed drugs for chronic weight management. Future modelling evaluations would benefit from a better understanding of the long-term weight loss effects of the current therapeutic options and the weight rebound process after the discontinuation of treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022302648, identifier CRD42022302648.

A Systematic Review of the Evidence for Non-surgical Weight Management for Adults with Severe Obesity: What is Cost Effective and What are the Implications for the Design of Health Services?

PURPOSE OF REVIEW

Severe obesity (BMI ≥ 35 kg/m²) increases premature mortality and reduces quality-of-life. Obesity-related disease (ORD) places substantial burden on health systems. This review summarises the cost-effectiveness evidence for non-surgical weight management programmes (WMPs) for adults with severe obesity.

RECENT FINDINGS

Whilst evidence shows bariatric surgery is often cost-effective, there is no clear consensus on the cost-effectiveness of non-surgical WMPs. Thirty-two studies were included. Most were short-term evaluations that did not capture the long-term costs and consequences of ORD. Decision models often included only a subset of relevant ORDs, and made varying assumptions about the rate of weight regain over time. A lack of sensitivity analyses limited interpretation of results. Heterogeneity in the definition of WMPs and usual care prevents formal evidence synthesis. We were unable to establish the most cost-effective WMPs. Addressing these limitations may help future studies provide more robust cost-effectiveness evidence for decision makers.

Incremental cost-effectiveness of evidence-based non-surgical weight loss strategies

Recent medical advancements have led to new modes of treatment for non-surgical weight loss, including several new medications. Our aim was to conduct an incremental cost-effectiveness analysis for all commercially available, evidence-based non-surgical weight loss interventions for people with excess weight. We identified interventions through a systematic review of randomized controlled trials that reported weight loss 12 months from baseline. We then meta-analysed the results, sourced costs and performed an incremental cost-effectiveness analysis from the payer perspective. Cost-effectiveness was presented in terms of cost per kilogram lost and quality-adjusted life years (QALY) gained. We further performed sensitivity analyses on costs and duration of benefits, and a probabilistic sensitivity analysis. Ten interventions were identified for inclusion: six pharmaceutical products (Alli, Xenical, Qsymia, Contrave, Belviq and Saxenda), two lifestyle modification programmes (Weight Watchers Meetings and Online), one food replacement and lifestyle programme (Jenny Craig) and one intragastric balloon system (Orbera). At an incremental cost-effectiveness ratio of $30 071 per additional QALY gained, only Weight Watchers Meetings was cost-effective. Sensitivity analyses revealed that for the medications to become incrementally cost-effective, costs would have to decrease by as much as 91%. Results are highly dependent on duration that benefits are maintained. Despite several newly available interventions, Weight Watchers Meetings is currently the only evidence-based, commercially available, cost-effective option for non-surgical weight loss. Other interventions, specifically medications, are more effective but priced too high to be cost-effective.

Bariatric surgery, lifestyle interventions and orlistat for severe obesity: the REBALANCE mixed-methods systematic review and economic evaluation

BACKGROUND

Adults with severe obesity [body mass index (BMI) of ≥ 35 kg/m2] have an increased risk of comorbidities and psychological, social and economic consequences.

OBJECTIVES

Systematically review bariatric surgery, weight-management programmes (WMPs) and orlistat pharmacotherapy for adults with severe obesity, and evaluate the feasibility, acceptability, clinical effectiveness and cost-effectiveness of treatment.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, PsycINFO, the Cochrane Central Register of Controlled Trials and the NHS Economic Evaluation Database were searched (last searched in May 2017).

REVIEW METHODS

Four systematic reviews evaluated clinical effectiveness, cost-effectiveness and qualitative evidence for adults with a BMI of ≥ 35 kg/m2. Data from meta-analyses populated a microsimulation model predicting costs, outcomes and cost-effectiveness of Roux-en-Y gastric bypass (RYGB) surgery and the most effective lifestyle WMPs over a 30-year time horizon from a NHS perspective, compared with current UK population obesity trends. Interventions were cost-effective if the additional cost of achieving a quality-adjusted life-year is < £20,000-30,000.

RESULTS

A total of 131 randomised controlled trials (RCTs), 26 UK studies, 33 qualitative studies and 46 cost-effectiveness studies were included. From RCTs, RYGB produced the greatest long-term weight change [-20.23 kg, 95% confidence interval (CI) -23.75 to -16.71 kg, at 60 months]. WMPs with very low-calorie diets (VLCDs) produced the greatest weight loss at 12 months compared with no WMPs. Adding a VLCD to a WMP gave an additional mean weight change of -4.41 kg (95% CI -5.93 to -2.88 kg) at 12 months. The intensive Look AHEAD WMP produced mean long-term weight loss of 6% in people with type 2 diabetes mellitus (at a median of 9.6 years). The microsimulation model found that WMPs were generally cost-effective compared with population obesity trends. Long-term WMP weight regain was very uncertain, apart from Look AHEAD. The addition of a VLCD to a WMP was not cost-effective compared with a WMP alone. RYGB was cost-effective compared with no surgery and WMPs, but the model did not replicate long-term cost savings found in previous studies. Qualitative data suggested that participants could be attracted to take part in WMPs through endorsement by their health-care provider or through perceiving innovative activities, with WMPs being delivered to groups. Features improving long-term weight loss included having group support, additional behavioural support, a physical activity programme to attend, a prescribed calorie diet or a calorie deficit.

LIMITATIONS

Reviewed studies often lacked generalisability to UK settings in terms of participants and resources for implementation, and usually lacked long-term follow-up (particularly for complications for surgery), leading to unrealistic weight regain assumptions. The views of potential and actual users of services were rarely reported to contribute to service design. This study may have failed to identify unpublished UK evaluations. Dual, blinded numerical data extraction was not undertaken.

CONCLUSIONS

Roux-en-Y gastric bypass was costly to deliver, but it was the most cost-effective intervention. Adding a VLCD to a WMP was not cost-effective compared with a WMP alone. Most WMPs were cost-effective compared with current population obesity trends.

FUTURE WORK

Improved reporting of WMPs is needed to allow replication, translation and further research. Qualitative research is needed with adults who are potential users of, or who fail to engage with or drop out from, WMPs. RCTs and economic evaluations in UK settings (e.g. Tier 3, commercial programmes or primary care) should evaluate VLCDs with long-term follow-up (≥ 5 years). Decision models should incorporate relevant costs, disease states and evidence-based weight regain assumptions.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016040190.

FUNDING

The National Institute for Health Research Health Technology Assessment programme. The Health Services Research Unit and Health Economics Research Unit are core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.

Current and emerging pharmacotherapy for prediabetes: are we moving forward?

INTRODUCTION

Prediabetes is a state wherein blood glucose levels are above normal but below the diagnostic threshold for diabetes. Seventy percent of patients with prediabetes develop type 2 diabetes in their lifetime. Despite this, prediabetes frequently goes undiagnosed.

AREAS COVERED

This review focuses on the pharmacological treatment of prediabetes and the prevention of progression to diabetes. A literature search was carried out on PubMed and Embase to review randomized controlled trials examining treatment of prediabetes. Emerging pharmacological therapies with potential benefit are discussed.

EXPERT OPINION

Lifestyle intervention is the cornerstone for preventing progression to diabetes, but metformin remains the first line pharmacological intervention. There appears to be minimal additive effect of combining metformin with lifestyle changes. It would be interesting to assess whether using combination pharmacological approaches plus or minus lifestyle interventions have any additive benefit. Despite the good level of evidence available, the penetrance of any interventions remains very low in part due to the prodromal categorization of the prediabetic state.

A feasibility randomised controlled trial of a motivational interviewing-based intervention for weight loss maintenance in adults

BACKGROUND

Obesity has significant health and NHS cost implications. Relatively small reductions in weight have clinically important benefits, but long-term weight loss maintenance (WLM) is challenging. Behaviour change interventions have been identified as key for WLM. Motivation is crucial to supporting behaviour change, and motivational interviewing (MI) has been identified as a successful approach to changing health behaviours. The study was designed as an adequately powered, pragmatic randomised controlled trial (RCT); however, owing to recruitment issues, the study became a feasibility trial.

OBJECTIVES

To assess recruitment, retention, feasibility, acceptability, compliance and delivery of a 12-month intervention to support WLM. Secondary objectives were to assess the impact of the intervention on body mass index (BMI) and other secondary outcomes.

DESIGN

Three-arm individually randomised controlled trial comprising an intensive arm, a less intensive arm and a control arm.

SETTING

Community setting in South Wales and the East Midlands.

PARTICIPANTS

Individuals aged 18-70 years with a current or previous BMI of ≥ 30 kg/m(2) who could provide evidence of at least 5% weight loss during the previous 12 months.

INTERVENTION

Participants received individually tailored MI, which included planning and self-monitoring. The intensive arm received six face-to-face sessions followed by nine telephone sessions. The less intensive arm received two face-to-face sessions followed by two telephone sessions. The control arm received a leaflet advising them on healthy lifestyle.

MAIN OUTCOME MEASURES

Feasibility outcomes included numbers recruited, retention and adherence. The primary effectiveness outcome was BMI at 12 months post randomisation. Secondary outcomes included waist circumference, waist-to-hip ratio, physical activity, proportion maintaining weight loss, diet, quality of life, health service resource usage, binge eating and well-being. A process evaluation assessed intervention delivery, adherence, and participants' and practitioners' views. Economic analysis aimed to assess cost-effectiveness in terms of quality-adjusted life-years (QALYs).

RESULTS

A total of 170 participants were randomised. Retention was good (84%) and adherence was excellent (intensive, 83%; less intensive, 91%). The between-group difference in mean BMI indicated the intensive arm had BMIs 1.0 kg/m(2) lower than the controls [95% confidence interval (CI) -2.2 kg/m(2) to 0.2 kg/m(2)]. Similarly, a potential difference was found in weight (average difference of 2.8 kg, 95% CI -6.1 kg to 0.5 kg). The intensive arm had odds of maintaining on average 43% [odds ratio(OR) 1.4, 95% CI 0.6 to 3.5] higher than controls. None of these findings were statistically significant. Further analyses controlling for level of adherence indicated that average BMI was 1.2 kg/m(2) lower in the intensive arm than the control arm (95% CI -2.5 kg/m(2) to 0.0 kg/m(2)). The intensive intervention led to a statistically significant difference in weight (mean -3.7 kg, 95% CI -7.1 kg to -0.3 kg). The other secondary outcomes showed limited evidence of differences between groups. The intervention was delivered as planned, and both practitioners and participants were positive about the intervention and its impact. Although not powered to assess cost-effectiveness, results of this feasibility study suggest that neither intervention as currently delivered is likely to be cost-effective in routine practice.

CONCLUSION

This is the first trial of an intervention for WLM in the UK, the intervention is feasible and acceptable, and retention and adherence were high. The main effectiveness outcome showed a promising mean difference in the intensive arm. Owing to the small sample size, we are limited in the conclusions we can draw. However, findings suggest that the intensive intervention may facilitate long-term weight maintenance and, therefore, further testing in an effectiveness trial may be indicated. Research examining WLM is in its infancy, further research is needed to develop our understanding of WLM and to expand theory to inform the development of interventions to be tested in rigorously designed RCTs with cost-effectiveness assessed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN35774128.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 50. See the NIHR Journals Library website for further project information.

Meta- and cost-effectiveness analysis of commercial weight loss strategies

OBJECTIVE

To estimate the incremental cost-effectiveness of clinically proven nonsurgical commercial weight loss strategies for those with BMIs between 25 and 40.

METHODS

We performed a systematic literature review to identify randomized controlled trials of commercially available weight loss studies of at least 1 year in duration. Using the results of these trials and publicly available cost data, we quantified the incremental cost per kilogram of weight loss and per quality adjusted life year (QALY) gained. We then use probabilistic sensitivity analyses to quantify uncertainty in our results.

RESULTS

Based on the literature review, two lifestyle programs (Weight Watchers and Vtrim), one meal replacement program (Jenny Craig), and three pharmaceutical products (Qsymia, Lorcaserin, and Orlistat) were included in the analysis. Average cost per kilogram of weight lost ranged from $155 (95% CI: $110-$218) for Weight Watchers to $546 (95% CI: $390-$736) for Orlistat. The incremental cost per QALY gained for Weight Watchers and Qsymia was $34,630 and $54,130, respectively. All other interventions were prohibitively expensive or inferior in that weight loss could be achieved at a lower cost through one or a combination of the other strategies.

CONCLUSIONS

Results suggest that, in the absence of other considerations and at current market prices, Weight Watchers and Qsymia represent the two most cost-effective strategies for nonsurgical weight loss.

Modelling the economics of type 2 diabetes mellitus prevention: a literature review of methods

Our objective was to review modelling methods for type 2 diabetes mellitus prevention cost-effectiveness studies. The review was conducted to inform the design of a policy analysis model capable of assisting resource allocation decisions across a spectrum of prevention strategies. We identified recent systematic reviews of economic evaluations in diabetes prevention and management of obesity. We extracted studies from two existing systematic reviews of economic evaluations for the prevention of diabetes. We extracted studies evaluating interventions in a non-diabetic population with type 2 diabetes as a modelled outcome, from two systematic reviews of obesity intervention economic evaluations. Databases were searched for studies published between 2008 and 2013. For each study, we reviewed details of the model type, structure, and methods for predicting diabetes and cardiovascular disease. Our review identified 46 articles and found variation in modelling approaches for cost-effectiveness evaluations for the prevention of type 2 diabetes. Investigation of the variables used to estimate the risk of type 2 diabetes suggested that impaired glucose regulation, and body mass index were used as the primary risk factors for type 2 diabetes. A minority of cost-effectiveness models for diabetes prevention accounted for the multivariate impacts of interventions on risk factors for type 2 diabetes. Twenty-eight cost-effectiveness models included cardiovascular events in addition to type 2 diabetes. Few cost-effectiveness models have flexibility to evaluate different intervention types. We conclude that to compare a range of prevention interventions it is necessary to incorporate multiple risk factors for diabetes, diabetes-related complications and obesity-related co-morbidity outcomes.

Estimating the potential annual welfare impact of innovative drugs in use in Switzerland

Expenditures of health care systems are increasing from year to year. Therefore, this study aimed to estimate the difference in costs and benefits of innovative pharmaceuticals launched 2000 onward compared to standard treatment on the national economy of Switzerland in 2010. The approach and formula described in the pilot study by Tsiachristas et al. (1), which analyzed the situation of welfare effects in the Netherlands, served as a model for our own calculations. A literature search was performed to identify cost-utility or cost-effectiveness studies of drugs launched 2000 onward compared to standard treatment. All parameters required for the calculation of welfare effects were derived from these analyses. The base-case threshold value of a quality-adjusted life year was set to CHF 100,000. Overall, 31 drugs were included in the welfare calculations. The introduction of innovative pharmaceuticals since 2000 onward to the Swiss market led to a potential welfare gain of about CHF 781 million in the year 2010. Univariate sensitivity analysis showed that results were robust. Probably because of the higher benefits of new drugs on health and quality of life compared to standard treatment, these drugs are worth the higher costs. The literature search revealed that there is a lack of information about the effects of innovative pharmaceuticals on the overall economy of Switzerland. Our study showed that potential welfare gains in 2010 by introducing innovative pharmaceuticals to the Swiss market were substantial. Considering costs and benefits of new drugs is important.

Predicting increased blood pressure using machine learning

The present study investigates the prediction of increased blood pressure by body mass index (BMI), waist (WC) and hip circumference (HC), and waist hip ratio (WHR) using a machine learning technique named classification tree. Data were collected from 400 college students (56.3% women) from 16 to 63 years old. Fifteen trees were calculated in the training group for each sex, using different numbers and combinations of predictors. The result shows that for women BMI, WC, and WHR are the combination that produces the best prediction, since it has the lowest deviance (87.42), misclassification (.19), and the higher pseudo R (2) (.43). This model presented a sensitivity of 80.86% and specificity of 81.22% in the training set and, respectively, 45.65% and 65.15% in the test sample. For men BMI, WC, HC, and WHC showed the best prediction with the lowest deviance (57.25), misclassification (.16), and the higher pseudo R (2) (.46). This model had a sensitivity of 72% and specificity of 86.25% in the training set and, respectively, 58.38% and 69.70% in the test set. Finally, the result from the classification tree analysis was compared with traditional logistic regression, indicating that the former outperformed the latter in terms of predictive power.

Economic evaluations of adult weight management interventions: a systematic literature review focusing on methods used for determining health impacts

BACKGROUND

One of the challenges when undertaking economic evaluations of weight management interventions is to adequately assess future health impacts. Clinical trials commonly measure impacts using surrogate outcomes, such as reductions in body mass index, and investigators need to decide how these can best be used to predict future health effects. Since obesity is associated with an increased risk of numerous chronic diseases occurring at different future time points, modelling is needed for predictions.

OBJECTIVE

To assess the methods used in economic evaluations to determine health impacts of weight management interventions and to investigate whether differences in methods affect the cost-effectiveness estimates.

METHODS

Eight databases were systematically searched. Included studies were categorized according to a decision analytic approach and effect measures incorporated.

RESULTS

A total of 44 articles were included; 21 evaluated behavioural interventions, 12 evaluated surgical procedures and 11 evaluated pharmacological compounds. Of the 27 papers that estimated future impacts, eleven used Markov modelling, seven used a decision tree, five used a mathematical application, two used patient-level simulation and the modelling method was unclear in two papers. The most common types of effects included were co-morbidity treatment costs, heath-related quality of life due to weight loss and gain in survival. Only 12 of the studies included heath-related quality of life gains due to reduced co-morbidities and only one study included productivity gains. Despite consensus that trial-based analysis on its own is inadequate in guiding resource allocation decisions, it was used in 39% of the studies. Several of the modelling papers used model structures not suitable for chronic diseases with changing health risks. Three studies concluded that the intervention dominated standard care; meaning that it generated more quality-adjusted life-years (QALYs) for less cost. The incremental costs per QALY gained varied from $US235 to $US56,836 in the remaining studies using this outcome measure. An implicit hypothesis of the review was that studies including long-term health effects would illustrate greater cost effectiveness compared with trial-based studies. This hypothesis is partly confirmed with three studies arriving at dominating results, as these reach their conclusion from modelling future co-morbidity treatment cost savings. However, for the remaining studies there is little indication that decision-analytic modelling disparities explain the differences.

CONCLUSIONS

This is the first literature review comparing methods used in economic evaluations of weight management interventions, and it is the first time that observed differences in study results are addressed with a view to methodological explanations. We conclude that many studies have methodological deficiencies and we urge analysts to follow recommended practices and use models capable of depicting long-term health consequences.

Economic effects of interventions to reduce obesity in Israel

BACKGROUND

Obesity is a major risk factor for many diseases. The paper calculates the economic impact and the cost per Quality-Adjusted Life Year (QALY) resulting from the adoption of eight interventions comprising the clinical and part of the community components of the National Prevention and Health Promotion Program (NPHPP) of the Israeli Ministry of Health (MOH) which represents the obesity control implementation arm of the MOH Healthy Israel 2020 Initiative.

METHODS

Health care costs per person were calculated by body mass index (BMI) by applying Israeli cost data to aggregated results from international studies. These were applied to BMI changes from eight intervention programmes in order to calculate reductions in direct treatment costs. Indirect cost savings were also estimated as were additional costs due to increased longevity of program participants. Data on costs and QALYs gained from Israeli and International dietary interventions were combined to provide cost-utility estimates of an intervention program to reduce obesity in Israel over a range of recidivism rates.

RESULTS

On average, persons who were overweight (25 ≤ BMI < 30)had health care costs that were 12.2% above the average health care costs of persons with normal or sub-normal weight to height ratios (BMI < 25). This differential in costs rose to 31.4% and 73.0% for obese and severely obese persons, respectively.For overweight (25 ≤ BMI < 30) and obese persons (30 ≤ BMI < 40), costs per person for the interventions (including the screening overhead) ranged from 35 NIS for a community intervention to 860 NIS, reflecting the intensity of the clinical setting intervention and the unit costs of the professionals carrying out the intervention [e.g., dietician]. Expected average BMI decreases ranged from 0.05 to 0.90. Higher intervention costs and larger BMI decreases characterized the two clinical lifestyle interventions for the severely obese (BMI ≥ 40).A program directed at the entire Israeli population aged 20 and over, using a variety of eight different interventions would cost 2.07 billion NIS overall. In the baseline scenario (with an assumed recidivism rate of 50% per annum), approximately 620,000,000 NIS would be recouped in the form of decreased treatment costs and indirect costs, increased productivity and decreased absenteeism. After discounting the 89,000,000 NIS additional health costs attributable to these extra life years, it is estimated that the total net costs to society would be 1.55 billion NIS. This total net cost was relatively stable to increases in the program's recidivism rates, but highly sensitive to reductions in recidivism rates.Under baseline assumptions, implementation of the cluster of interventions would save 32,671 discounted QALYs at a cost of only 47,559 NIS per QALY, less than half of the Israeli per capita GNP (104,000 NIS). Thus implementation of these components of the NPHPP should be considered very cost-effective.

CONCLUSION

Despite the large costs of such a large national program to control obesity, cost-utility analysis strongly supports its introduction.

Cost-effectiveness of pharmacotherapy to reduce obesity

AIMS

Obesity causes a high disease burden in Australia and across the world. We aimed to analyse the cost-effectiveness of weight reduction with pharmacotherapy in Australia, and to assess its potential to reduce the disease burden due to excess body weight.

METHODS

We constructed a multi-state life-table based Markov model in Excel in which body weight influences the incidence of stroke, ischemic heart disease, hypertensive heart disease, diabetes mellitus, osteoarthritis, post-menopausal breast cancer, colon cancer, endometrial cancer and kidney cancer. We use data on effectiveness identified from PubMed searches, on mortality from Australian Bureau of Statistics, on disease costs from the Australian Institute of Health and Welfare, and on drug costs from the Department of Health and Ageing. We evaluate 1-year pharmacological interventions with sibutramine and orlistat targeting obese Australian adults free of obesity-related disease. We use a lifetime horizon for costs and health outcomes and a health sector perspective for costs. Incremental Cost-Effectiveness Ratios (ICERs) below A$50 000 per Disability Adjusted Life Year (DALY) averted are considered good value for money.

RESULTS

The ICERs are A$130 000/DALY (95% uncertainty interval [UI] 93 000-180 000) for sibutramine and A$230 000/DALY (170 000-340 000) for orlistat. The interventions reduce the body weight-related disease burden at the population level by 0.2% and 0.1%, respectively. Modest weight loss during the interventions, rapid post-intervention weight regain and low adherence limit the health benefits.

CONCLUSIONS

Treatment with sibutramine or orlistat is not cost-effective from an Australian health sector perspective and has a negligible impact on the total body weight-related disease burden.

Health state preferences associated with weight status in children and adolescents

BACKGROUND

Childhood obesity is a substantial public health problem. The extent to which health state preferences (utilities) are related to a child's weight status has not been reported. The aims of this study were (1) to use a generic health state classification system to measure health related quality of life and calculate health utilities in a convenience sample of children and adolescents and (2) to determine the extent to which these measures are associated with weight status and body mass index (BMI).

METHODS

We enrolled 76 children 5-18 years of age from a primary care clinic and an obesity clinic in Boston MA. We administered the Health Utilities Index (HUI) and used the HUI Mark 3 single- and multi-attribute utility functions to calculate health utilities. We determined BMI percentile and weight status based on CDC references. We examined single-attribute and overall utilities in relation to weight status and BMI.

RESULTS

Mean (range) age was 10.8 (5-18) years. Mean (SD) BMI percentile was 76 (26); 55% of children were overweight or obese. The mean (SD) overall utility was 0.79 (0.17) in the entire sample. For healthy-weight children, the mean overall utility was higher than for overweight or obese children (0.81 vs. 0.78), but the difference was not statistically significant (difference 0.04, 95% CI -0.04, 0.11).

CONCLUSIONS

Our results provide a quantitative estimate of the health utility associated with overweight and obesity in children, and will be helpful to researchers performing cost effectiveness analyses of interventions to prevent and/or treat childhood obesity.

Forecasting the effects of obesity and smoking on U.S. life expectancy

BACKGROUND

Although increases in obesity over the past 30 years have adversely affected the health of the U.S. population, there have been concomitant improvements in health because of reductions in smoking. Having a better understanding of the joint effects of these trends on longevity and quality of life will facilitate more efficient targeting of health care resources.

METHODS

For each year from 2005 through 2020, we forecasted life expectancy and quality-adjusted life expectancy for a representative 18-year-old, assuming a continuation of past trends in smoking (based on data from the National Health Interview Survey for 1978 through 1979, 1990 through 1991, 1999 through 2001, and 2004 through 2006) and past trends in body-mass index (BMI) (based on data from the National Health and Nutrition Examination Survey for 1971 through 1975, 1988 through 1994, 1999 through 2002, and 2003 through 2006). The 2003 Medical Expenditure Panel Survey was used to examine the effects of smoking and BMI on health-related quality of life.

RESULTS

The negative effects of increasing BMI overwhelmed the positive effects of declines in smoking in multiple scenarios. In the base case, increases in the remaining life expectancy of a typical 18-year-old are held back by 0.71 years or 0.91 quality-adjusted years between 2005 and 2020. If all U.S. adults became nonsmokers of normal weight by 2020, we forecast that the life expectancy of an 18-year-old would increase by 3.76 life-years or 5.16 quality-adjusted years.

CONCLUSIONS

If past obesity trends continue unchecked, the negative effects on the health of the U.S. population will increasingly outweigh the positive effects gained from declining smoking rates. Failure to address continued increases in obesity could result in an erosion of the pattern of steady gains in health observed since early in the 20th century.

Cost-effectiveness of a low-calorie diet and orlistat for obese persons: modeling long-term health gains through prevention of obesity-related chronic diseases

OBJECTIVE

Our study estimated the cost-effectiveness of pharmacologic treatment of obesity in combination with a low-calorie diet in The Netherlands.

METHODS

Costs and effects of a low-calorie diet-only intervention and of a low-calorie diet in combination with 1 year of orlistat were compared to no treatment. The RIVM Chronic Disease Model was used to project the differences in quality adjusted life years (QALYs) and lifetime health-care costs because of the effects of the interventions on body mass index (BMI) status. This was done by linking BMI status to the occurrence of obesity-related diseases and by relating quality of life to disease status. Probabilistic sensitivity analysis was employed to study the effect of uncertainty in the model parameters. In univariate sensitivity analysis, we assessed how sensitive the results were to several key assumptions.

RESULTS

Incremental costs per QALY gained were Euro 17,900 for the low-calorie diet-only intervention compared to no intervention and Euro 58,800 for the low-calorie diet + orlistat compared to the low-calorie diet only. Assuming a direct relation between BMI and quality of life, these ratios decreased to Euro 6000 per QALY gained and Euro 24,100 per QALY gained. Costs per QALY gained were also sensitive to assumptions about long-term weight loss maintenance.

CONCLUSIONS

Cost-effectiveness ratios of interventions aiming at weight reduction depend strongly on assumptions regarding the relation between BMI and quality of life. We recommend that a low-calorie diet should be the first option for policymakers in combating obesity.

Cost-effectiveness of pharmacological anti-obesity treatments: a systematic review

AIM

To review economic evaluations of weight loss drugs and compare reported incremental cost-effectiveness ratios (ICERs).

METHODS

A literature search was conducted for cost-effectiveness (CEAs) and cost-utility analyses (CUAs) of sibutramine, orlistat and rimonabant.

RESULTS

Fourteen unique articles were identified (11 CUAs and 3 CEAs; 9 orlistat, 4 sibutramine and 1 rimonabant). All used diet and exercise as comparator, whereas none included indirect costs. Time horizons varied from treatment period only (1-4 years) to 80 years (median 7.5 years). Longer studies modeled effects on diabetes, micro- and macrovascular complications, coronary heart disease and death. Of the CUAs, the median ICER was 16,000 euro(2007)/QALY (quality-adjusted life-year; range 10,000-88,000), with the worst cost-effectiveness when recommended stop rules for non-responding patients were not applied. All studies but three were funded by the manufacturing company, and the median ICER was considerably higher for independent than for sponsored analyses (62,000 euro vs 15,000 euro/QALY). However, two of the three independent CUAs did not use recommended stop rules, as compared with one of eight manufacturer-sponsored analyses. The results were most sensitive to assumptions regarding weight loss sustainability and utility per kilogram lost. Side effects and dropout because of reasons other than lack of efficacy were generally not incorporated.

CONCLUSION

Published economic evaluations indicate that orlistat, sibutramine and rimonabant are within the range of what is generally regarded as cost-effective. Uncertainty remains about weight loss sustainability, utility gain associated with weight loss and extrapolations from transient weight loss to long-term health benefits. Modeling of head-to-head comparisons and attrition is needed, as are analyses conducted independently of manufacturing companies.

Uncertainty in decision-making: value of additional information in the cost-effectiveness of lifestyle intervention in overweight and obese people

OBJECTIVES

To quantify the uncertainty in the cost-effectiveness of lifestyle intervention versus standard care in overweight and obese people in Switzerland and to determine if further research is necessary based on current information. There has been an increasing interest in using value of information analysis in medical decision-making to quantify the uncertainty in decision-making, and to identify the need for further research.

METHODS

Value of information analysis was applied on a probabilistic cost-effectiveness model to evaluate the uncertainty by calculating the patient expected value of perfect information (EVPI), population EVPI, and partial EVPI. The costs were expressed in Swiss Francs (CHF), price year 2006.

RESULTS

Overall, the EVPI was higher in overweight than in obese people. The maximum population EVPI was CHF 6.8 million in overweight people and CHF 3.2 million in moderate obese people, representing the upper limit on costs associated with decision uncertainty. The partial EVPI estimated a higher uncertainty in the model parameters such as utilities, body mass index, cardiovascular risk factors, and systolic blood pressure in overweight and moderate obese subjects.

CONCLUSIONS

The EVPI analysis indicates that there is some uncertainty regarding the choice between lifestyle intervention and standard care. The parameter EVPI suggests that if further research is commissioned, this should focus on the effectiveness of lifestyle intervention on cardiovascular risk factors and utilities.

Cost-utility analysis of rimonabant in the treatment of obesity

OBJECTIVE

To estimate the incremental cost-utility ratio (ICUR) of rimonabant 20 mg/day in the treatment of obesity from a third-party payer's perspective.

METHODS

Pooled data from three randomized clinical trials were used to develop a decision tree with five treatment alternatives: 1- and 2-year treatment with rimonabant, 2-year placebo, 1-year rimonabant followed by 1-year placebo, and no treatment. All alternatives, except no treatment, were accompanied by lifestyle interventions. Treatment benefits included gains in quality-adjusted life-years (QALYs) and reduced incidence of type-2 diabetes mellitus and coronary heart disease (CHD). Drug acquisition cost was based on the average wholesale price of a comparator drug minus 15%. One-way and probabilistic sensitivity analyses were conducted to assess the stability of the base-case results.

RESULTS

One-year rimonabant and 1-year rimonabant followed by placebo were extensively dominated. Rimonabant for 2 years showed an average weight reduction of 8.49 kg, a body mass index reduction of 2.98 kg/m(2) and reduced waist circumference by 8.24 cm (placebo: 3.55 kg, 1.22 kg/m(2), 4.18 cm). Two-year rimonabant was associated with a relative reduction in the 5-year incidence of CHD by 7.15% and of diabetes by 9.28%. Incremental benefits (costs) were 0.0984 QALYs ($5209) compared to no treatment and 0.0581 QALYs ($4182) compared to placebo, producing ICURs of $52,936/QALY (95% confidence interval $39K-$69K) and $71,973/QALY ($51K-$98K), respectively.

CONCLUSIONS

Rimonabant combined with lifestyle interventions has the potential to decrease the rate of obesity-related comorbidities and improve health-related quality of life, albeit at considerable cost.

Economic evaluation of treatment with orlistat in Italian obese patients

The XENDOS study showed that behavioural and pharmacological therapy can decrease the risk of metabolic disorders in obese patients.

METHODS

A probabilistic Bayesian Markov model simulating the outcomes of orlistat treatment on the obese Italian population has been developed with the WinBUGS software. The model integrates an algorithm to estimate cardiovascular risk based on Framingham Heart Study equations. Analyses adopted the societal cost perspective, including direct medical costs borne by both the National Health Service and the patient, since orlistat is not included in the Italian reimbursement list.

RESULTS

The simulation on the Italian obese population estimated an average increase in quality-adjusted life expectancy, a reduction of cardiovascular events and new diabetes cases. The average incremental cost-utility ratio is euro75.3 (7.6-180.6) x 1000/QALY. The subgroup analysis showed that the benefits are relatively greater in older patients and in patients with impaired glucose tolerance (IGT). Two hypotheses have been explored to estimate the impact of a potential reimbursement decision by the Italian NHS: (1) orlistat is given to every obese patient; (2) orlistat is given only to obese IGT patients with a previous glucose tolerance general screening program to assess their eligibility. The cost utility of the strategies are euro42.3 (-22.16-108.7) and euro10.16 (-60.4-38.76) x 1000/QALY, respectively.

CONCLUSION

Orlistat shows a good pharmacoeconomic profile and, in particular, the strategy of a screening programme to identify and treat the IGT subgroup has a cost-utility value of about euro10000/QALY. This value is lower than that of several therapeutic strategies commonly accepted and reimbursed in developed countries.