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

Health state utilities associated with weight loss in type 2 diabetes and obesity

INTRODUCTION

Health state utilities associated with weight change are needed as inputs for cost-utility analyses (CUAs) examining the value of treatments for obesity and type 2 diabetes (T2D). Although some pharmaceutical treatments currently in development are associated with substantial weight loss, little is known about the utility impact of weight decreases greater than 10%. The purpose of this study was to estimate utilities associated with body weight decreases up to 20% based on preferences of individuals with obesity, with and without T2D.

METHODS

Health state vignettes were developed to represent respondents' own current weight and weight decreases of 2.5, 5, 10, 15, and 20%. Health state utilities were elicited in time trade-off interviews in two UK locations (Edinburgh and London) with a sample of participants with obesity, with and without T2D. Mean utility increases associated with each amount of weight decrease were calculated. Regression analyses were performed to derive a method for estimating utility change associated with weight decreases.

RESULTS

Analyses were conducted with data from 405 individuals with obesity (202 with T2D, 203 without T2D). Utility increases associated with various levels of weight decrease ranged from 0.011 to 0.060 in the subgroup with T2D and 0.015 to 0.077 in the subgroup without T2D. All regression models found that the percentage of weight decrease was a highly significant predictor of change in utility (p < .0001). The relationship between weight change and utility change did not appear to be linear. Equations are recommended for estimating utility change based on the natural logarithm of percentage of weight decrease.

DISCUSSION

Results of this study may be used to provide inputs for CUAs examining and comparing the value of treatments that are associated with substantial amounts of weight loss in patients with obesity, with or without T2D.

Assessment of Quality of Life 8-Dimension (AQoL-8D): translation, validation, and application in two Dutch trials in patients with epilepsy and schizophrenia

BACKGROUND

To translate and linguistically validate the Assessment of Quality of Life 8-dimensions (AQoL-8D) for use in the Netherlands and to compare the psychometric properties of AQoL-8D with the EuroQol 5-dimensions 5-levels (EQ-5D-5L) in two patient samples.

METHODS

AQoL-8D was translated from English into Dutch. The translated AQoL-8D was then administered alongside the EQ-5D-5L at baseline and follow-up of two Dutch randomized controlled trials among patients with epilepsy and schizophrenia. These data were subjected to a post-hoc analysis assessing the psychometric properties of AQol-8D vis-à-vis EQ-5D-5L in terms of known-groups construct validity, responsiveness, and floor/ceiling effects.

RESULTS

In total, 103 epilepsy patients and 99 schizophrenia patients were included in this study. In both datasets, the two instruments discriminated between known-groups, but in schizophrenia, AQoL-8D showed higher responsiveness than EQ-5D-5L, while both instruments showed equal responsiveness in epilepsy. Ceiling effects were only found for EQ-5D-5L in both epilepsy (26.6%) and schizophrenia (6.1%).

CONCLUSION

Our results have shown that, among other things, AQoL-8D presents better ability to discriminate between known-groups and shows no ceiling effect. Based on our results, we would recommend the use of AQoL-8D in addition to EQ-5D-5L in trials assessing patient's quality of life in patients with epilepsy or schizophrenia.

Psychometric properties of the EQ-5D-5L: a systematic review of the literature

PURPOSE

Although the EQ-5D has a long history of use in a wide range of populations, the newer five-level version (EQ-5D-5L) has not yet had such extensive experience. This systematic review summarizes the available published scientific evidence on the psychometric properties of the EQ-5D-5L.

METHODS

Pre-determined key words and exclusion criteria were used to systematically search publications from 2011 to 2019. Information on study characteristics and psychometric properties were extracted: specifically, EQ-5D-5L distribution (including ceiling and floor), missing values, reliability (test-retest), validity (convergent, known-groups, discriminate) and responsiveness (distribution, anchor-based). EQ-5D-5L index value means, ceiling and correlation coefficients (convergent validity) were pooled across the studies using random-effects models.

RESULTS

Of the 889 identified publications, 99 were included for review, representing 32 countries. Musculoskeletal/orthopedic problems and cancer (n = 8 each) were most often studied. Most papers found missing values (17 of 17 papers) and floor effects (43 of 48 papers) to be unproblematic. While the index was found to be reliable (9 of 9 papers), individual dimensions exhibited instability over time. Index values and dimensions demonstrated moderate to strong correlations with global health measures, other multi-attribute utility instruments, physical/functional health, pain, activities of daily living, and clinical/biological measures. The instrument was not correlated with life satisfaction and cognition/communication measures. Responsiveness was addressed by 15 studies, finding moderate effect sizes when confined to studied subgroups with improvements in health.

CONCLUSIONS

The EQ-5D-5L exhibits excellent psychometric properties across a broad range of populations, conditions and settings. Rigorous exploration of its responsiveness is needed.

A systematic review and meta-analysis of health state utility values for osteoarthritis-related conditions

BACKGROUND

Health state utility values (HSUVs) are a key input in health economic modelling but HSUVs of people with osteoarthritis (OA)-related conditions have not been systematically reviewed and meta-analysed.

OBJECTIVE

To systematically review and meta-analyse the HSUVs for people with OA.

METHODS

Searches within health economic/biomedical databases were performed to identify eligible studies reporting OA-related HSUVs. Data on study design, participant characteristics, affected OA joint sites, treatment type, HSUV elicitation method, considered health states, and the reported HSUVs were extracted. HSUVs for people with knee, hip and mixed OA in pre- and post-treatment populations were meta-analysed using random effects models.

RESULTS

One-hundred and fifty-one studies were included in the systematic review, and 88 in meta-analyses. Of 151 studies, 56% were conducted in Europe, 75% were in people with knee and/or hip OA and 79% were based on the EQ-5D. The pooled mean (95% confidence interval [CI]) baseline HSUVs for knee OA core interventions, medication, injection and primary surgery treatments were 0.64 (0.61-0.66), 0.56 (0.45-0.68), 0.58 (0.50-0.66) and 0.52 (0.49-0.55), respectively. These were 0.71 (0.59-0.84) for hip OA core interventions and 0.52 (0.49-0.56) for hip OA primary surgery. For all knee OA treatments and hip OA primary surgery, pooled HSUVs were significantly higher in the post- than the pre- treatment populations.

CONCLUSION

This study provides a comprehensive summary of OA-related HSUVs and generates a HSUVs database for people with different affected OA joint sites undergoing different treatments to guide HSUV choices in future health economic modelling of OA interventions.

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.

Prospective Analysis Regarding Health-Related Quality of Life (HR-QOL) between Morbid Obese Patients Following Bariatric Surgery Versus on a Waiting List

BACKGROUND

Major impairment of health-related quality of life (HRQoL) is one of the main reasons why obese patients request surgical treatment.

OBJECTIVE

To prospectively analyze the impact of HRQoL between obese patients who underwent surgery and those who were wait-listed.

METHODS

Between April 2017 and March 2018, 70 surgical and 69 wait-listed patients were interviewed twice, at baseline and at the 12-month follow-up. Quality of life was measured by the SF-12v2 and the Impact of Weight on Quality of Life-Lite (IWQoL-Lite) questionnaires. Sociodemographic-, clinical-, and surgical-related variables were collected.

RESULTS

One hundred thirty-nine patients were analyzed, showing similar baseline characteristics but differences in HRQoL. Performing more qualified work improved scores on some aspects of the SF-12 survey. In contrast, women scored worse on the self-esteem domain, and men scored worse on the mental health domain. By group, at the 12-month follow-up, statistically significant differences were found among all aspects of the questionnaires between both groups (P < 0.001) and between baseline and postoperative 12-month follow-up in the surgical group (P < 0.001). Furthermore, scores were lower in all domains in the evolution of wait-listed patients, with statistically significant differences among the Bodily Pain, Emotional Role, Mental Health, and Mental Component Summary Domains (P < 0.05).

CONCLUSION

HRQoL is a multimodal concept that allows the identification of factors impacting obese patients' quality of life. It promotes the benefit of surgery against waiting list delays, which can take up to 4 years in our hospital. Therefore, HRQoL is an important pillar to justify more resources for reducing unacceptable surgical delays.

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.

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.

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.