Bariatric Surgery: Cost-Effectiveness and Budget

Bariatric Surgery: Cost-Effectiveness and Budget Impact

Lorenzo Terranova, Luca Busetto, Annarita Vestri & Marco Antonio Zappa

Obesity Surgery The Journal of Metabolic Surgery and Allied Care ISSN 0960-8923 Volume 22 Number 4 OBES SURG (2012) 22:646-653 DOI 10.1007/s11695-012-0608-1

1 23

Your article is protected by copyright and all rights are held exclusively by Springer Science + Business Media, LLC. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your work, please use the accepted author’s version for posting to your own website or your institution’s repository. You may further deposit the accepted author’s version on a funder’s repository at a funder’s request, provided it is not made publicly available until 12 months after publication.

1 23

Author's personal copy OBES SURG (2012) 22:646–653 DOI 10.1007/s11695-012-0608-1

REVIEW

Bariatric Surgery: Cost-Effectiveness and Budget Impact Lorenzo Terranova & Luca Busetto & Annarita Vestri & Marco Antonio Zappa

Published online: 31 January 2012 # Springer Science+Business Media, LLC 2012

Abstract Bariatric surgery is to date the most effective treatment for morbid obesity and it has been proven to reduce obesity-related comorbidities and total mortality. As any medical treatment, bariatric surgery is costly and doubts about its affordability have been raised. On the other hand, bariatric surgery may reduce the direct and indirect costs of obesity and related comorbidities. The appreciation of the final balance between financial investments and savings is critical from a health economic perspective. In this paper, we try to provide a brief updated review of the most recent studies on the cost-efficacy of bariatric surgery, with particular emphasis on budget analysis. A brief overview of the L. Terranova Federazione Italiana Aziende Sanitarie e Ospedaliere (FIASO), Scuola di Specializzazione in Statistica Sanitaria, Università di Roma “La Sapienza”, Rome, Italy L. Busetto Unità Bariatrica, Dipartimento di Medicina, Università degli Studi di Padova, Padua, Italy A. Vestri Dipartimento di Sanità Pubblica e Malattie Infettive, Facoltà di Farmacia e Medicina, Università di Roma “La Sapienza”, Rome, Italy M. A. Zappa Unità Operativa Complessa Chirurgia Generale, Ospedale “Sacra Famiglia” Fatebenefratelli, Erba, Italy L. Busetto (*) Clinica Medica I, Policlinico Universitario, Via Giustiniani 2, 35128 Padua, Italy e-mail: [email protected]

economic costs of obesity will also be provided. The epidemic of obesity may cause a significant reduction in life expectancy and overwhelming direct and indirect costs for citizens and societies. Cost-efficacy analyses included in this review consistently demonstrated that the additional years of lives gained through bariatric surgery may be obtained at a reasonable and affordable cost. In groups of patients with very high obesity-related health costs, like patients with type 2 diabetes, the use of bariatric surgery required an initial economic investment, but may save money in a relatively short period of time. Keywords Bariatric surgery . Cost-effectiveness . Gastric banding . Gastric bypass . Type 2 diabetes

Introduction Bariatric surgery is to date the most effective treatment for morbid obesity. The efficacy of bariatric procedures in the induction and maintenance of weight loss largely superior to that obtainable by current medical therapies has been confirmed by large meta-analyses [1, 2]. This sustained weight loss has a profound impact on obesity-related comorbidities, type 2 diabetes in particular. According to a meta-analysis including the results of 621 original studies with 888 treatment arms and 135,246 patients, diabetic patients had an overall 78.1% resolution of the clinical manifestations of diabetes after surgery, and diabetes was improved or resolved in 86.6% [2]. The results of these largely uncontrolled studies have been confirmed by the findings of the Swedish Obese Subjects (SOS) study, a long-term prospective study comparing the outcomes of bariatric surgery and conventional treatment in matched morbidly obese patients [3]. The superiority of bariatric surgery over medical therapy in the management of obese

Author's personal copy OBES SURG (2012) 22:646–653

patients with type 2 diabetes has been proven also by a small randomized controlled trial [4]. Finally, the SOS study demonstrated that bariatric surgery, as compared to conventional treatment, was associated to a reduction of total mortality [5]. This finding has been confirmed by other seven retrospective case–control studies [6–12]. These studies have been recently meta-analyzed by Pontiroli and Morabito [13], who confirmed a global 45.0% reduction in total mortality. As any medical treatment, bariatric surgery has a cost. Moreover, as typical for surgery, the costs appear to be concentrated in a short period, generally the year of the procedure. This figure requires an initial financial investment, and giving the huge number of morbidly obese patients potentially treatable, this investment may be elevated in total for private or public managed health systems. Doubts about the affordability of these costs have been raised. On the other hand, bariatric surgery may save some money in a longer perspective, reducing the direct costs associated to the management of obesity and related comorbidities and the indirect costs related to the loss of productivity caused by premature mortality and work disability. The appreciation of the final balance between financial investments and savings is critical from a health economic perspective. In this paper, we try to provide a brief updated review of the most recent studies on the cost-efficacy of bariatric

647

surgery. Cost-efficacy will be analyzed in particular at a general managed care level, in budget analysis. A brief overview of the economic costs of obesity will also be provided. In order to familiarize the readers with some technical pharmacoeconomic terms used along the text, a brief glossary is included in Table 1.

The Economic Costs of Obesity Economic costs generated by obesity are usually divided into direct and indirect costs. Direct costs are those related to the behavioral and pharmacological treatment of obesity itself and, most importantly, to the long-term complex management of obesity-related comorbidities. Indirect costs are the costs paid by the patients and the society in terms of loss of work productivity due to sick leave and long-term work disability and loss of years of productive lives due to obesity-related premature mortality. The sum of direct and indirect costs multiplied by the total number of obese patients generates an enormous total spending all over the world [14], and according to some opinions, direct costs may represent 2–7% of the total world health costs [15]. A study endorsed by the National Audit Office in the UK estimated that the annual direct cost related

Table 1 Glossary of pharmacoeconomic terms BI CEA

CMA CUA Effectiveness Efficacy Efficiency ICER QALY(s)

Sensitivity analysis

[Budget impact]. The financial impact of the introduction of a technology or service on the capital and operating budgets of a government or agency or a hospital [Cost-effectiveness analysis]. In a CEA, new therapies are compared with existing ones, or with placebo/no treatment, on both effectiveness and efficacy. A comparison of alternative interventions in which costs are measured in monetary units and outcomes are measured in non-monetary units, e.g., reduced mortality or morbidity [Cost minimization analysis]. A determination of the least costly among alternative interventions that are assumed to produce equivalent outcomes [Cost utility analysis]. A form of cost-effectiveness analysis of alternative interventions in which costs are measured in monetary units and outcomes are measured in terms of their utility, usually to the patient, e.g., using QALYs The benefit (e.g., to health outcomes) of using a technology for a particular problem under general or routine conditions, for example, by a physician in a community hospital or by a patient at home The benefit of using a technology for a particular problem under ideal conditions, for example, in a laboratory setting, within the protocol of a carefully managed randomized controlled trial, or at a “center of excellence” The extent to which the maximum possible benefit is achieved out of available resources [Incremental cost-effectiveness ratio]. The additional cost of the more expensive intervention as compared with the less expensive intervention divided by the difference in effect or patient outcome between the interventions, e.g., additional cost per QALY [Quality-adjusted life year(s)]. QALY is frequently used as a measure of effectiveness in CEA. A unit of health care outcomes that adjusts gains (or losses) in years of life subsequent to a health care intervention by the quality of life during those years. QALYs can provide a common unit for comparing cost utility across different interventions and health problems. QALY is calculated multiplying the years of life spent in a specific health state by a measure of quality of life ranging usually from 0 (a health state comparable with death) to 1 (a health state comparable with perfect health). In brief, QALY is an expression of how much life of years in good quality of life is gained by using a new treatment. A means to determine the robustness of a mathematical model or analysis (such as a cost-effectiveness analysis or decision analysis) that tests a plausible range of estimates of key independent variables (e.g., costs, outcomes, probabilities of events) to determine if such variations make meaningful changes the results of the analysis. Sensitivity analysis also can be performed for other types of study, e.g., clinical trial analysis (to see if inclusion/exclusion of certain data changes results) and meta-analysis (to see if inclusion/exclusion of certain studies changes results)

Author's personal copy 648

OBES SURG (2012) 22:646–653

to obesity management for the UK National Health System (NHS) was 9.5 million of UK pounds (£) in 1998 [16]. However, the annual NHS cost related to the management of obesity-related comorbidities peaked to UK £469.9 million [16], giving a total estimation of about UK £480 million for annual direct costs, representing 1.5% of total NHS annual spending. The National Institute for Health and Clinical Excellence (NICE), in a more recent report [17], estimated an additional UK £2 billion for indirect costs in the UK. In the USA, by using a different definition of direct and indirect costs, Levi et al. estimate a national annual 75 billion US dollars (US$) for direct costs and US $64 billion for indirect costs, summing to a total of US $139 billion, roughly a 5% of the US national health expenditure in 2009 [18]. Finally, a Canadian study estimated 1.6 billion of Canadian dollars (CDN$) for direct costs and CDN $2.7 billion for indirect costs in 2001, with the total economic costs of obesity representing 2.2% of the total health care costs in Canada [19].

costs [21]. A study commissioned by Kaiser Permanente Medical Care Program, a private, non-profit, prepaid group practice program, confirmed a higher use of both inpatient and outpatient services in people with high BMI levels [22]. As previously reported, a significant proportion of the excess health care costs associated to obesity is related to the management of obesity-related comorbidities. In Table 3, the relative risk of several associated diseases in the obese population is reported. At the US population level, the higher risk of several diseases observed in the obese population translates into a huge number of subjects potentially affected by the diseases and in large incremental costs [23]. Obesity-related incremental cost is small in younger subjects, but it tends to increase with age, driven by the high prevalence of diabetes and coronary heart disease [24]. According to recent estimates, annual medical expenditures would be between 6.7% and 10.7% lower across US states in the absence of obesity [25].

Direct Costs of Obesity

Indirect Costs of Obesity

Some of the most interesting studies [14, 18, 20, 21] evaluating the increment in direct health costs associated to obesity are summarized in Table 2. Obese patients have been shown to have higher costs for both in-hospital and out-of-hospital care. The increment in drug spending seems to be particularly high. In a direct health care cost study conducted on 35,932 patients from a US insurance registry, a J-shaped relationship between BMI and health care costs has been observed. The increment in health care costs associated to an increase in BMI from 25 to 45 kg/m2 was US $119.7 for medical care and US $82.6 for pharmacological

Indirect costs of obesity are related to a loss in productivity caused by premature mortality, disability, and absenteeism. Indirect costs are more difficult to define than direct costs and may vary according to the methodologies and estimations used for their calculation. Anyway, indirect costs of obesity are believed to be considerably high. In the USA, annual indirect costs of obesity have been estimated to US $48 billion [23] or to US $64 billion [18], with most of the costs attributed to premature mortality. At the world level, indirect costs of obesity have been estimated by a different study to be US $58.8 billion, a figure similar to the indirect

Table 2 Direct costs of obesity Index

Comparisons

Results

Reference number

Aggregate costs

Obese patients vs. nonobese patients

[14]

Medicines (with prescription) Physical and psychological examinations Hospital time

Class I and class II obese patients vs. nonobese patients Class I and class II obese patients vs. nonobese patients

Obese patients have higher costs compared to nonobese patients (+42.0%; + US $1,429) Obese patients have higher costs compared to nonobese patients (+80.4%; + US $568) Obese patients have higher costs compared to nonobese patients (+26.9%; + US $444) Obese patients have higher costs compared to nonobese patients (+45.5%; + US $420) On average, obese patients spend more than 36% compared to nonobese patients for health care services On average, obese patients spend more than 77% compared to nonobese patients for medicines For each additional point of BMI compared to normal BMI, costs increase to 4% For each additional point of BMI compared to normal BMI, costs increase to 7%

[20]

Aggregate costs

Class I and class II obese patients vs. nonobese patients Obese patients vs. nonobese patients

Medicines


Health costs


Medicines


[20] [20]

[18] [18] [21] [21]

Author's personal copy OBES SURG (2012) 22:646–653

649

Table 3 Relative risk of comorbidities in the obese subjects, percent of the population at risk for the disease, and incremental direct costs in the US population (from [23]) Comorbidities

Type 2 diabetes

Relative risk

PAR (%)

Direct costs (in US$ billion)

11.0

69

36.6

CHD

4.0

40

16.2

Hypertension Gall bladder disease

4.0 5.5

40 50

7.6 4.3

Breast cancer

1.3

7

0.5

Endometrium cancer Colon cancer

2.5 1.5

27 10

0.2 0.9

Osteoarthritis

2.1

20

Total

3.6 69.9

PAR indicates population attributable risk (percent). PAR is calculated with the following formula: PAR ¼ pðRR 1Þ=1 þ pðRR 1Þ , where p is the prevalence of the exposure in the population and RR is the relative risk for disease

costs caused by smoking [26]. At the individual level, the negative social and economic consequences of obesity seem to be more worrisome in women than in men [27]. Obese workers generally have higher work absenteeism than their normal weight colleagues, suffering from an increased loss of work hours due to sick leave. In an American study on full-time employees, the percentage of workers who lost work hours in the 2 weeks before the survey was significantly higher in obese (42.3%) than in normal weight (36.4%) workers (p