Updated: Sep 20
Increasing the number of bariatric and metabolic surgeries (BMS) would be expected to reduce COVID-19-related morbidity and mortality, as well as obesity-related co-morbidities, and ultimately reduce the clinical and economic burden of obesity, according to UK researchers. One of their key findings was only nine patients had to be treated to save one life. The outcomes were featured in the paper, ‘Cost-effectiveness of bariatric and metabolic surgery, and implications of COVID-19 in the United Kingdom’, published in SOARD.
The study, led by researchers from North Bristol NHS Trust, Southmead Hospital, Bristol, UK, stated that people living with obesity have been among those most disproportionately impacted by the COVID-19 pandemic, highlighting the urgent need for increased provision of (BMS). Therefore, the authors wanted to evaluate the possible clinical and economic benefits of BMS vs with non-surgical treatment options in the UK, considering the broader impact that COVID-19 has on people living with obesity.
The researchers developed a Markov model and compared lifetime costs and outcomes of BMS and conventional treatment among patients with body mass index (BMI) ≥40kg/m2, BMI≥35 kg/m2 with obesity-related co-morbidities (Group A), or BMI≥35 kg/m2 with type 2 diabetes (T2D; Group B). Inputs were sourced from clinical audit data and literature sources; direct and indirect costs were considered. Model outputs included costs and quality-adjusted life years (QALYs). Scenario analyses whereby patients experienced COVID-19 infection, BMS was delayed by five years and BMS patients underwent endoscopy were conducted.
The analysis compared laparoscopic gastric bypass and laparoscopic sleeve gastrectomy, and conventional treatment was defined as supervised diet and exercise programs with or without pharmacotherapy.
Costs included the cost of treatment and the costs associated with each co-morbidity. Where possible, unit costs were derived from NHS reference costs (inflated to 2019 GBP (£) values); all costs were UK-specific. Societal impact was measured by incorporating productivity losses/gains, based on employment rate, and work impairment, into the model, which were dependent on BMI. Model outputs included costs and QALYs, which were used to calculate the cost-effectiveness of BMS vs. conventional treatment, represented as incremental cost-effectiveness ratios (ICER; the difference in cost between 2 interventions, divided by the difference in their effect [QALYs]).
The mean age (standard deviation [SD]) was 46.45 (10.68) years and 51.74 (8.37) years for Group A and B, respectively. The mean BMI (SD) was 48.90 (7.37) kg/m2 and 49.15 (8.48) kg/m2 for Group A and B, respectively. BMS was found to be the dominant strategy (lower costs and higher QALYs) over conventional treatment, in both group, from the healthcare payer perspective. In addition, BMS also had lower rates of T2DM, stroke, myocardial infarction, cancer, knee pain, and sleep apnoea and lower costs associated with these co-morbidities. BMS resulted in an incremental net monetary benefit (NMB) of £110,024 in Group A, and £64,495 in Group B, at a willingness-to-pay (WTP) threshold of £25,000/QALY gained.
They also reported that BMS was cost saving for the NHS service after 12 years in Group A and five years in Group B. Considering a societal perspective, the total costs per patient following BMS were lower than those for conventional treatment, in both populations; it took two and four years of running an NHS service for BMS to be cost saving in Group A and B, respectively.
Across 1,000 patients with COVID-19 in Group A, the model predicted that BMS would prevent 117 deaths, 124 hospital admissions and 161 ICU admissions due to COVID-19, compared with if they received conventional therapy. In Group B, the model predicted that 64 deaths, 65 hospital admissions and 90 ICU admissions due to COVID-19 would be prevented.
The number needed to treat to avoid one death was nine patients in Group A and 16 patients in Group B.
When COVID-19 infections were considered, BMS remained dominant, resulting in an increase in both survival years and QALYs and a reduction in total costs versus conventional treatment.
Other key findings included:
Compared with the base case (no consideration of COVID-19 infection), BMS was associated with a per-patient increase in incremental survival years (+2.12 and +1.04 in Group A and Group B, respectively), QALYs (+.37 and +.08, respectively) and incremental costs (+£3,889 and +£4,082, respectively).
Compared with the base case, NMB remained positive, increasing by £5,298 to £115,322 in Group A and decreasing by £2,027 to £62,468 in Group B.
The results of the COVID-19 scenario analyses were most sensitive to variation in the risk of COVID-19–related death per BMI unit.
In Group A and Group B, delaying BMS by five years was associated with less cost savings (−4.2% and −12.3%, respectively), fewer QALYs gained (−10.2% and −4.5%, respectively) and a reduction in survival years (−8.6% and −5.7%, respectively) vs. not delaying the treatment.
Compared with the base case, NMB remained positive, decreasing by £11,381 to £98,643 in Group A, and by £3,284 to £61,211 in Group B. BMS was dominant versus conventional treatment in both groups.
“The cost-effectiveness of BMS was higher when COVID-19 infections were considered or access to surgery was delayed, due to increased morbidity and mortality,” the authors concluded.
This study was funded by Johnson & Johnson.
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