Diverse approaches to the health economic evaluation of bariatric surgery: a comprehensive systematic review

Global strategies to reduce elective surgery waiting times for sustainable health outcomes: a systematic review

OBJECTIVE

Long waiting times for elective surgery reflect not just backlog issues but systemic inefficiencies that disrupt the smooth flow of patients through the surgical care pathway. This systematic review adopts a holistic approach to summarize global policies, strategies, and interventions aimed at reducing elective surgery wait times.

METHOD

A comprehensive electronic search was performed in PubMed, EMBASE, SCOPUS, Web of Science, and Cochrane Library from December 2019 to January 2020 and updated in April 2022. Eligible studies, published after 2013, focused on waiting lists for major elective surgeries in adults, excluding cancer-related surgeries. Both randomized and non-randomized studies and systematic reviews were included. Study quality was assessed using ROBINS-I, AMSTAR 2, and CASP tools, as appropriate. The review was registered in PROSPERO (CRD42019158455) and reported using a PRISMA flow diagram.

RESULTS

From 7543 records, 92 articles met the inclusion criteria. Evidence was categorized into seven strategic areas: referral management, patient prioritization, preventing scheduled surgery cancellations, perioperative time management, quality improvement methods for surgical care pathways, and waiting time targets for hospitals. Strategies such as referral management, patient prioritization, and preventing cancellations had the most significant impact on reducing waiting times, while perioperative time management and waiting time targets proved less effective.

CONCLUSION

The review highlights that targeted interventions at different stages of the surgical care pathway yield variable impacts on overall waiting times. While individual measures had limited effects, combining multiple short-term strategies may be more beneficial, particularly for health systems recovering from the COVID-19 pandemic.

Investigation of the health economic analysis of informal care for people living with a chronic neurological disease: A systematic review and meta-analysis of the global evidence for multiple sclerosis

Multiple sclerosis (MS) is a chronic neurological disease that causes substantial health economic impacts, however, the cost of informal care for MS is often excluded from health economic analysis. As a result there is a paucity of information for decision-making. This review aims to summarise, synthesise and where appropriate meta-analyse the global evidence regarding the health economics of informal care for people with MS. The findings will provide consolidated evidence that policymakers and other stakeholders can use to inform decisions, including the development of health economics models. This review was conducted with a pre-determined study protocol (PROSPERO- CRD42023396457). Biomedical and economic databases were searched. Costs were converted to 2022 United States dollars (USD). Mean cost was calculated and pooled with a random-effects model. Subgroup analysis and meta-regression was conducted for stratified variables such as country income level and Expanded Disability Status Scale (EDSS). Of 6,306 identified studies, 61 were retained for narrative synthesis and 50 for meta-analysis. Studies were conducted in 25 countries. Cost information was collected from the person with MS, not the caregiver. 83.6% of studies used the opportunity cost method. Average monthly caregiving time was 60.1 h. Informal care costs accounted for 15% of total societal cost of MS. Pooled mean annual cost of informal care per person was USD $6,308 (95% CI $5,022-7,594). Informal care costs were USD $6,797 and $1,478 in high- and middle-income countries. Costs for mild, moderate, and severe disability of the person with MS were $1,123, $6,643, and $15,855, respectively. Informal care cost contributes considerably to MS-related costs. Despite study heterogeneity, cost of informal care increases with MS-related disability severity, time attributed to care and country income level. These results can be used to inform health economic models for reimbursement decisions for MS. Future studies regarding the health economic burden of informal care should gather the data from the informal carers themselves.

Economic Evaluations of Anti-obesity Interventions in Obese Adults: An Umbrella Review

This umbrella review amalgamates the outcomes of economic evaluations pertaining to bariatric surgeries, pharmacotherapy, and gastric balloon for adult obesity treatment. Six databases were systematically searched. The inclusion criteria were established following the Patient/population Intervention Comparison and Outcomes (PICO) statement. Fifteen reviews met all the inclusion criteria. Eight studies focused on surgical interventions, four on pharmacotherapy, and three on both interventions. No systematic review of the economic evaluation of gastric balloons was identified. The majority of reviews advocated bariatric surgery as a cost-effective approach; however, there was discordance in the interpretation of pharmacological cost-effectiveness. Most of the economic evaluations were conducted from the payer and the healthcare system perspectives. We propose that future economic evaluations assessing weight loss interventions in adults adopt a societal perspective and longer-term time horizons.

Clinical outcomes and adverse events of bariatric surgery in adults with severe obesity in Scotland: the SCOTS observational cohort study

Background

Bariatric surgery is a common procedure worldwide for the treatment of severe obesity and associated comorbid conditions but there is a lack of evidence as to medium-term safety and effectiveness outcomes in a United Kingdom setting.

Objective

To establish the clinical outcomes and adverse events of different bariatric surgical procedures, their impact on quality of life and the effect on comorbidities.

Design

Prospective observational cohort study.

Setting

National Health Service secondary care and private practice in Scotland, United Kingdom.

Participants

Adults (age >16 years) undergoing their first bariatric surgery procedure.

Main outcome measures

Change in weight, hospital length of stay, readmission and reoperation rate, mortality, diabetes outcomes (HbA1c, medications), quality of life, anxiety, depression.

Data sources

Patient-reported outcome measures, hospital records, national electronic health records (Scottish Morbidity Record 01, Scottish Care Information Diabetes, National Records Scotland, Prescription Information System).

Results

Between December 2013 and February 2017, 548 eligible patients were approached and 445 participants were enrolled in the study. Of those, 335 had bariatric surgery and 1 withdrew from the study. Mean age was 46.0 (9.2) years, 74.7% were female and the median body mass index was 46.4 (42.4; 52.0) kg/m2. Weight was available for 128 participants at 3 years: mean change was -19.0% (±14.1) from the operation and -24.2% (±12.8) from the start of the preoperative weight-management programme. One hundred and thirty-nine (41.4%) participants were readmitted to hospital in the same or subsequent 35 months post surgery, 18 (5.4% of the operated cohort) had a reoperation or procedure considered to be related to bariatric surgery gastrointestinal complications or revisions. Fewer than five participants (<2%) died during follow-up. HbA1c was available for 93/182 and diabetes medications for 139/182 participants who had type 2 diabetes prior to surgery; HbA1c mean change was -5.72 (±16.71) (p = 0.001) mmol/mol and 65.5% required no diabetes medications (p < 0.001) at 3 years post surgery. Physical quality of life, available for 101/335 participants, improved in the 3 years post surgery, mean change in Rand 12-item Short Form Survey physical component score 8.32 (±8.95) (p < 0.001); however, there was no change in the prevalence of anxiety or depression.

Limitations

Due to low numbers of bariatric surgery procedures in Scotland, recruitment was stopped before achieving the intended 2000 participants and follow-up was reduced from 10 years to 3 years.

Conclusions

Bariatric surgery is a safe and effective treatment for obesity. Patients in Scotland, UK, appear to be older and have higher body mass than international comparators, which may be due to the small number of procedures performed.

Future work

Intervention studies are required to identify the optimal pre- and post surgery pathway to maximise safety and cost-effectiveness.

Study registration

This study is registered as ISRCTN47072588.

Funding details

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 10/42/02) and is published in full in Health Technology Assessment; Vol. 28, No. 7. See the NIHR Funding and Awards website for further award information.

Cost-effectiveness of metabolic surgery for the treatment of type 2 diabetes and obesity: a systematic review of economic evaluations

AIM

To systematically identify and appraise the international literature on the cost-effectiveness of metabolic surgery for the treatment of comorbid type 2 diabetes (T2D) and obesity.

METHODS

A systematic search was conducted in electronic databases and grey literature sources up to 20 January 2021. Economic evaluations in a T2D population or a subpopulation with T2D were eligible for inclusion. Screening, data extraction, critical appraisal of methodological quality (Consensus Health Economic Criteria list) and assessment of transferability (International Society for Pharmacoeconomics and Outcomes Research questionnaire) were undertaken in duplicate. The incremental cost-effectiveness ratio (ICER) was the main outcome. Costs were reported in 2020 Irish Euro. Cost-effectiveness was interpreted using willingness-to-pay (WTP) thresholds of €20,000 and €45,000/quality-adjusted life year (QALY). Due to heterogeneity arising from various sources, a narrative synthesis was undertaken.

RESULTS

Thirty studies across seventeen jurisdictions met the inclusion criteria; 16 specifically in a T2D population and 14 in a subpopulation with T2D. Overall, metabolic surgery was found to be cost-effective or cost-saving. Where undertaken, the results were robust to sensitivity and scenario analyses. Of the 30 studies included, 15 were considered high quality. Identified limitations included limited long-term follow-up data and uncertainty regarding the utility associated with T2D remission.

CONCLUSION

Published high-quality studies suggest metabolic surgery is a cost-effective or cost-saving intervention. As the prevalence of obesity and obesity-related diseases increases worldwide, significant investment and careful consideration of the resource requirements needed for metabolic surgery programmes will be necessary to ensure that service provision is adequate to meet demand.

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.

Resource utilization and disaggregated cost analysis of bariatric surgery in the Australian public healthcare system

OBJECTIVES

To present a comprehensive real-world micro-costing analysis of bariatric surgery.

METHODS

Patients were included if they underwent primary bariatric surgery (gastric banding [GB], gastric bypass [GBP] and sleeve gastrectomy [SG]) between 2013 and 2019. Costs were disaggregated into cost items and average-per-patient costs from the Australian healthcare systems perspective were expressed in constant 2019 Australian dollars for the entire cohort and subgroup analysis. Annual population-based costs were calculated to capture longitudinal trends. A generalized linear model (GLM) predicted the overall bariatric-related costs.

RESULTS

N = 240 publicly funded patients were included, with the waitlist times of ≤ 10.7 years. The mean direct costs were $11,269. The operating theatre constituted the largest component of bariatric-related costs, followed by medical supplies, salaries, critical care use, and labour on-costs. Average cost for SG ($12,632) and GBP ($15,041) was higher than that for GB ($10,049). Operating theatre accounted for the largest component for SG/GBP costs, whilst medical supplies were the largest for GB. We observed an increase in SG and a decrease in GB procedures over time. Correspondingly, the main cost driver changed from medical supplies in 2014-2015 for GB procedures to operating theatre for SG thereafter. GLM model estimates of bariatric average cost ranged from $7,580 to $36,633.

CONCLUSIONS

We presented the first detailed characterization of the scale, disaggregated profile and determinants of bariatric-related costs, and examined the evolution of resource utilization patterns and costs, reflecting the shift in the Australian bariatric landscape over time. Understanding these patterns and forecasting of future changes are critical for efficient resource allocation.

Incremental Net Monetary Benefit of Bariatric Surgery: Systematic Review and Meta-Analysis of Cost-Effectiveness Evidences

This systematic review aimed to comprehensively synthesize cost-effectiveness evidences of bariatric surgery by pooling incremental net monetary benefits (INB). Twenty-eight full economic evaluation studies comparing bariatric surgery with usual care were identified from five databases. In high-income countries (HICs), bariatric surgery was cost-effective among mixed obesity group (i.e., obesity with/without diabetes) over a 10-year time horizon (pooled INB = $53,063.69; 95% CI $42,647.96, $63,479.43) and lifetime horizon (pooled INB = $101,897.96; 95% CI $79,390.93, $124,404.99). All studies conducted among obese with diabetes reported that bariatric surgery was cost-effective. Also, the pooled INB for obesity with diabetes group over lifetime horizon in HICs was $80,826.28 (95% CI $32,500.75, $129,151.81). Nevertheless, no evidence is available in low- and middle-income countries.

Health state utilities for economic evaluation of bariatric surgery: A comprehensive systematic review and meta-analysis

Health state utilities (HSUs) are health economic metrics that capture and assess health-related quality of life (HRQoL). They are essential in health-economic evaluations when calculating quality-adjusted life years. We investigated published studies reporting bariatric surgery-related HSUs elicited through direct or indirect (multiattribute utility instrument [MAUI]) patient-reported methods (PROSPERO registration number: CRD42019131725). Mean HSUs for different time points and HSU changes over time (where feasible) were meta-analysed using random-effects models. Of the 950 potentially relevant identified studies, n = 28 (2004-2018) qualified for data extraction, with n = 85 unique HSUs elicited mainly from the EQ-5D (88%). Most (75%) studies were published after 2013. The follow-up duration varied between studies and was often limited to 12 months. The pooled mean HSU was 0.72 (0.67-0.76) at baseline/presurgery (n = 18) and 0.84 (0.79-0.89) one-year postsurgery (n = 11), indicating a 0.11 (0.09-0.14) utility unit increment. EQ-5D showed the similar results. This positive difference can be partially explained by BMI and/or co-morbidities status improvement. This study provides a valuable summary of HSUs to future bariatric surgery-related cost-utility models. However, more well-designed higher-quality bariatric-related HSU studies are expected for future reviews to improve the available evidence. We suggest that researchers select an MAUI that is preferentially sensitive to the study population.

Economic evaluation of surgical treatment of obesity

INTRODUCTION

Obesity surgery is the best treatment for extreme obesity, with demonstrated long-term positive outcomes. The potential cost-savings generated by the improvement of comorbidities after surgery can justify the allocation of more resources in the surgical treatment of obesity.

METHODS

This was an observational, descriptive, longitudinal and retrospective study. Eligible patients underwent Roux-en-Y gastric bypass surgery at the Hospital Universitario Central de Asturias between 2003 and 2012. The established minimum follow-up period was two years. We calculated the individualized cost per patient treated (bottom-up) as well as per Diagnosis-Related Group (DRG) codes (top-down).

RESULTS

Our study included 307 patients. The average cost per hospitalization calculated by DRG codes was €6,545.90, and the average cost per patient was €10,572.20. DRG 288 represented 91% of the series, with a value of €4,631. The number of medications also decreased during this period, from 2.86 to 0.78 per medically treated patient, representing a cost reduction of €4,433 per patient with all the obesity-related comorbidities analyzed.

CONCLUSIONS

Two years after Roux-en-Y gastric bypass conducted at Hospital Universitario Central de Asturias, the savings in drug costs for patients with multiple pathologies would compensate the inherent costs of the surgical treatment itself. Our results showed that DRG-related costs was insufficient to make a correct economic evaluation, so we recommend an individualized cost calculating method.

Multi-Centre Micro-Costing of Roux-En-Y Gastric Bypass, Sleeve Gastrectomy and Adjustable Gastric Banding Procedures for the Treatment of Severe, Complex Obesity

BACKGROUND

There is a growing interest in comparing the effectiveness and costs of alternative forms of bariatric surgery. We aimed to examine the per-patient, procedural costs of Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG) and adjustable gastric banding (AGB) in the United Kingdom.

METHODS

Multi-centre (two National Health Service; NHS and one private hospital) micro-costing, using a time-and-motion study. Prospective collection of surgery times, staff quantities, equipment, instruments and consumables for 12 patients (four RYGB, five SG, three AGB) from patients' first surgeon interaction on the day of surgery to departure from the theatre recovery area. Costs were attached to quantities and mean costs compared. Sensitivity and scenario analyses assessed the impact of varying surgery inputs and consideration of additional plausible factors respectively on total costs.

RESULTS

Mean procedural costs were £5002 for RYGB, £4306 for SG and £2527 for AGB. Varying staff seniority or altering procedure times had small impacts on costs (± 4-6%). Reducing prices of consumables by 20% reduced costs by 10-13%. Accounting for differences in surgical technique by altering the number of staple reloads used impacted costs by ± 7-10%. Adjusted total costs from scenario analyses were similar to NHS tariffs for RYGB and SG (difference of £51 and -£119 respectively) but were much lower for AGB (difference of £1982).

CONCLUSIONS

These detailed costs will allow for more precise reimbursement of bariatric surgery and support comprehensive assessments of cost-effectiveness. Additional work to investigate costs of post-surgical care, re-operations and life-long support received by patients following surgery is required.

Bariatric surgery is a cost-saving treatment for obesity-A comprehensive meta-analysis and updated systematic review of health economic evaluations of bariatric surgery

Demand for bariatric surgery to treat severe and resistant obesity far outstrips supply. We aimed to comprehensively synthesise health economic evidence regarding bariatric surgery from 1995 to 2018 (PROSPERO registration number: CRD42018094189). Meta-analyses were conducted to calculate the annual cost changes "before" and "after" surgery, and cumulative cost differences between surgical and nonsurgical groups. An updated narrative review also summarized the full and partial health economic evaluations of surgery from September 2015. N = 101 studies were eligible for the qualitative analyses since 1995, with n = 24 studies after September 2015. Quality of reporting has increased, and the inclusion of complications/reoperations was predominantly contained in the full economic evaluations after September 2015. Technical improvements in surgery were also reflected across the studies. Sixty-one studies were eligible for the quantitative meta-analyses. Compared with no/conventional treatment, surgery was cost saving over a lifetime scenario. Additionally, consideration of indirect costs through sensitivity analyses increased cost savings. Medication cost savings were dominant in the before versus after meta-analysis. Overall, bariatric surgery is cost saving over the life course even without considering indirect costs. Health economists are hearing the call to present higher quality studies and include the costs of complications/reoperations; however, indirect costs and body contouring surgery are still not appropriately considered.

Long-Term Inpatient Hospital Utilisation and Costs (2007-2008 to 2015-2016) for Publicly Waitlisted Bariatric Surgery Patients in an Australian Public Hospital System Based on Australia's Activity-Based Funding Model

BACKGROUND

Within the Australian public hospital setting, no studies have previously reported total hospital utilisation and costs (pre/postoperatively) and costed patient-level pathways for primary bariatric surgery and surgical sequelae (including secondary surgery) informed by Australia's Independent Hospital Pricing Authority's activity-based funding (ABF) model.

OBJECTIVE

We aimed to provide our Tasmanian state government partner with information regarding key evidence gaps about the resource use and costs of bariatric surgery (including pre- and postoperatively, types of surgery and comorbidities), the costs of surgical sequelae and policy direction regarding the types of bariatric surgery offered within the Tasmanian public hospital system.

METHODS

Hospital inpatient length of stay (days), episodes of care (number) and aggregated cost data were extracted for people who were waiting for and subsequently received bariatric surgery (for the fiscal years 2007-2008 to 2015-2016) from administrative sources routinely collected, clinically coded/costed according to ABF. Aggregated ABF costs were expressed in 2016-2017 Australian dollars ($A). Sensitivity (cost outliers) and subgroup analyses were conducted.

RESULTS

A total of 105 patients entered the study. Total costs (pre/postoperative over 8 years) for all inpatient episodes of care (n = 779 episodes of care) were $A6,018,349. When the ten cost outliers were omitted from the total cost, this cost reduced to $A4,749,265. Mean costs for primary laparoscopic adjustable gastric band (LAGB) and sleeve gastrectomy (SG) bariatric surgery were $A14,622 and $A15,014, respectively. The average cost/episode of care for people with diabetes decreased in the first year postoperatively, from $A7258 to $A5830/episode of care. In total, 27 LAGB patients (30%) required surgery due to surgical sequelae (including revisional/secondary surgery; n = 58 episodes of care) and 56% of these episodes of care were secondary LAGB device related (mostly port/reservoir related), with a mean cost of $A6267.

CONCLUSIONS

Taking into account our small SG sample size and the short time horizon for investigating surgical sequalae for SG, costs may be mitigated in the Tasmanian public hospital system by substituting LAGB with SG when clinically appropriate due to costs associated with the LAGB device for some patients. At 3 years postoperatively versus preoperatively, episodes of care and costs reduced substantially, particularly for people with diabetes/cardiovascular disease. We recommend that a larger confirmatory study of bariatric surgery including LAGB and SG be undertaken of disaggregated ABF costs in the Tasmanian public hospital system.

Variations in bariatric surgical care pathways: a national costing study on the variability of services and impact on costs

BACKGROUND

We undertook a survey of all bariatric centres in Scotland in order to describe current pre- and post-operative care, to estimate their costs and explore differences in financial impact.

METHODS

A questionnaire was distributed to each health centre. Descriptive statistics were used to present average cost per patient along with 95% confidence intervals, and the range of costs.

RESULTS

Results show nearly a five-fold difference in costs per patient for pre-operative services (range £226 - £1071) and more than a three-fold difference for post-operative services (range £259 - £896).

CONCLUSIONS

There is a lack of evidence base and a clear requirement for the evaluation of bariatric surgical services to identify the care pathways pre- and post-surgery which lead to largest improvements in health outcomes and remain cost-effective.

An Exploratory Study: A Head-to-Head Comparison of the EQ-5D-5L and AQoL-8D for Long-Term Publicly Waitlisted Bariatric Surgery Patients Before and 3 Months After Bariatric Surgery

BACKGROUND

Choice of a multi-attribute utility instrument (MAUI) that appropriately assesses an intervention's health-related quality-of-life (HRQoL) impacts is a vital part of healthcare resource allocation and clinical assessment.

OBJECTIVE

Our exploratory study compared the EuroQol (EQ)-5D-5L and Assessment of Quality of Life (AQoL)-8D MAUIs, which were used to assess the effect of bariatric surgery for a cohort of long-term publicly waitlisted, severely obese patients.

METHODS

The study was conducted at the Hobart Private Hospital (Tasmania, Australia). To compare the sensitivity and instrument content of the two MAUIs, we used dimensional comparisons by investigating the distribution of patient-reported responses (number/percentage) across the MAUIs' levels and dimensions; summary health-state utility valuations (utilities); and individual/super-dimension scores (AQoL-8D) to investigate discriminatory power and HRQoL improvements preoperatively and 3 months postoperatively.

RESULTS

Participants' (n = 23) overall MAUI completion rate was 74%. Postoperative total weight loss was 9.9%. EQ-5D-5L utilities were relatively higher pre- and postoperatively than AQoL-8D utilities [mean standard deviation (SD) EQ-5D-5L 0.70 (0.25) to 0.80 (0.25); AQoL-8D 0.51 (0.24) to 0.61 (0.24)]. AQoL-8D Psychosocial super dimension was relatively low postoperatively [0.37 (0.25)], driving the instrument's lower utility. These results were supported by the dimensional comparisons that revealed an overall greater dispersion for the AQoL-8D. Nevertheless, there were clinical improvements in utilities for both instruments. AQoL-8D utilities were lower than population norms; not so the EQ-5D-5L utilities. The AQoL-8D dimensions of Happiness, Coping, and Self-worth improved the most.

CONCLUSIONS

AQoL-8D more fully captured the impact of obesity and bariatric surgery on HRQoL (particularly psychosocial impacts) for long-term waitlisted bariatric surgery patients, even 3 months postoperatively. AQoL-8D preoperative utility revealed our population's HRQoL was lower than people with cancer or heart disease.

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.

A qualitative investigation of the health economic impacts of bariatric surgery for obesity and implications for improved practice in health economics

Obesity is an economic problem. Bariatric surgery is cost-effective for severe and resistant obesity. Most economic evaluations of bariatric surgery use administrative data and narrowly defined direct medical costs in their quantitative analyses. Demand far outstrips supply for bariatric surgery. Further allocation of health care resources to bariatric surgery (particularly public) could be stimulated by new health economic evidence that supports the provision of bariatric surgery. We postulated that qualitative research methods would elicit important health economic dimensions of bariatric surgery that would typically be omitted from the current economic evaluation framework, nor be reported and therefore not considered by policymakers with sufficient priority. We listened to patients: Focus group data were analysed thematically with software assistance. Key themes were identified inductively through a dialogue between the qualitative data and pre-existing economic theory (perspective, externalities, and emotional capital). We identified the concept of emotional capital where participants described life-changing desires to be productive and participate in their communities postoperatively. After self-funding bariatric surgery, some participants experienced financial distress. We recommend a mixed-methods approach to the economic evaluation of bariatric surgery. This could be operationalised in health economic model conceptualisation and construction, through to the separate reporting of qualitative results to supplement quantitative results.

Systematic assessment of decision analytic models for the cost-effectiveness of bariatric surgery for morbid obesity

Bariatric surgery among patients with morbid obesity is very effective for providing long-term weight loss and remission of obesity-related co-morbidities. However, it is very expensive and its cost effectiveness is commonly argued. Long-term cost-effectiveness evaluations of bariatric surgery have often relied on decision models. A systematic review was performed on the methodologic approaches and their quality, evaluated the quality of reporting, and summarized findings and conclusions in published cost-effectiveness models of bariatric surgery for morbid obesity. A search from different databases with an end date of October 15, 2017 was completed. The initial search for title and abstract screening resulted in 741 articles. A total of 50 articles were included for full-text review and 23 economic evaluation studies were included in the systematic review. The reporting quality scores of most articles were rated as acceptable between 61% and 100%. Most studies (89%) were modeled for adult patients with age range between 25 and 75 years old. Sixty-one percent of studies defined their health states by the existence or absence of different obesity-related co-morbidities. Eleven percent of studies took the societal perspective. Most studies (61%) used a lifetime horizon. Thirty-nine percent of studies identified the extent of weight loss as the most sensitive and influential parameter. Seventeen (74%) did not report a formal model validation. Laparoscopic Roux-en-Y gastric bypass was reported as the most cost-effective strategy most often when it compared with no treatment or medical management. While most had acceptable quality of reporting levels, several gaps in the quality of reporting and quality of methods emerged, which led to recommendations for how to improve quality in future studies.

An Exploratory Study of Long-Term Publicly Waitlisted Bariatric Surgery Patients' Quality of Life Before and 1 Year After Bariatric Surgery, and Considerations for Healthcare Planners

BACKGROUND

Long-term publicly waitlisted bariatric surgery patients typically experience debilitating physical/psychosocial obesity-related comorbidities that profoundly affect their quality of life.

OBJECTIVES

We sought to measure quality-of-life impacts in a study population of severely obese patients who had multiyear waitlist times and then underwent bariatric surgery.

METHODS

Participants were recruited opportunistically following a government-funded initiative to provide bariatric surgery to morbidly obese long-term waitlisted patients. Participants self-completed the EQ-5D-5L and AQoL-8D questionnaires pre- and postoperatively. Utility valuations (utilities) and individual/super dimension scores (AQoL-8D only) were generated.

RESULTS

Participants' (n = 23) waitlisted time was mean [standard deviation (SD)] 6.5 (2) years, body mass index reduced from 49.3 (9.35) kg/m² preoperatively to 40.8 (7.01) 1 year postoperatively (p = 0.02). One year utilities revealed clinical improvements (both instruments). AQoL-8D improved significantly from baseline to 1 year, with the change twice that of the EQ-5D-5L [EQ-5D-5L: mean (SD) 0.70 (0.25) to 0.78 (0.25); AQoL-8D: 0.51 (0.24) to 0.67 (0.23), p = 0.04], despite the AQoL-8D's narrower algorithmic range. EQ-5D-5L utility plateaued from 3 months to 1 year. AQoL-8D 1-year utility improvements were driven by Happiness/Coping/Self-worth (p < 0.05), and the Psychosocial super dimension score almost doubled at 1 year (p < 0.05). AQoL-8D revealed a wider dispersion of individual utilities.

CONCLUSIONS

Ongoing improvements in psychosocial parameters from 3 months to 1 year post-surgery accounted for improvements in overall utilities measured by the AQoL-8D that were not detected by EQ-5D-5L. Selection of a sensitive instrument is important to adequately assess changes in quality of life and to accurately reflect changes in quality-adjusted life-years for cost-utility analyses and resource allocation in a public healthcare resource-constrained environment.