Bariatric treatments for adult obesity - Institute of Health Economics

latter to be more cost-effective, driven by fewer post-operative complications, and noted adifference in health care and productivity costs. van Mastrigt et al. 11 compared vertical bandedgastroplasty (VBG) with Lap-Band over a 1-year horizon, based on an RCT enrolling 100 patients.This study indicated that VBG was associated with an extra $143 per additional per cent excessweight loss. In the Clegg study, AGB and gastric bypass were shown to be more cost-effective thanVBG, with a cost of $10,131 and $1217, respectively, per QALY gained.In conclusion, the CADTH report 1 stated that, compared to lifestyle modification, bariatric surgerywas cost-effective for patients with severe obesity and, furthermore, was less costly and moreeffective for those with T2DM. However, the report suggested that no conclusion was achievedregarding the cost-effectiveness between the surgical alternatives, due to limitations in the reviewedprimary studies.Pharmacotherapy (PT) versus lifestyle modification (LM), weight management program(WMP), or no treatmentEight studies 14-21 compared PT plus LM with LM alone. Two studies 22,23 evaluated PT alone versusno treatment and one study 24 evaluated PT plus WMP versus WMP alone. Van Baal et al. 14conducted a Markov model to compare low-calorie diet (LCD) alone with no treatment and tocompare LCD plus orlistat with no treatment for adult patients between 20 and 70 years of age witha BMI ≥ 30 kg/m 2 . The analysis was conducted in the Netherlands from a payer’s perspective over alifetime horizon. Estimates of short-term efficacy were derived from published literature, and longtermefficacy rates were based on the assumption that 23% of weight loss achieved after 1 yearwould be maintained over the patient’s lifetime. This analysis considered the cost of health care(including GP and dietitian time), orlistat acquisition, and the treatment for obesity-related morbidity.Compared with no treatment, the cost per life year gained and the cost per QALY gained were$22,177 and $24,140, respectively, for LCD alone, and $72,286 and $79,299 for LCD plus orlistat.The study concluded that LCD should be the first option for the treatment of obesity for adultsaged 20 to 70 years with a BMI ≥ 30 kg/m 2 .Lacey et al. 15 constructed a decision-tree model to assess the cost-effectiveness of LCD plus orlistat,as compared to LCD alone for patients aged 18 years or older with a BMI ≥ 28 kg/m 2 and nodiagnosed T2DM. The analysis was conducted in Ireland from a payer’s perspective using an 11-yearhorizon. Estimates of efficacy were derived from five RCTs. The treatment period was 12 months.For patients with less than 5% weight loss at the third month, the orlistat treatment would bediscontinued. Costs considered in the analysis were the acquisition cost of orlistat, the cost of theLCD program, and the cost associated with monitoring and treatment of obesity-related morbidity.Compared to LCD alone, the cost per QALY gained was $22,864 for LCD plus orlistat. The studyconcluded that orlistat is effective and cost-effective compared to LCD alone.Iannazzo et al. 16 constructed a Markov model to assess the long term (10 years) clinical andeconomic impact of orlistat in combination with LM (LCD and exercise) versus LM alone for adultpatients in Italy with a BMI ≥ 30 kg/m 2 . Clinical evidence applied in the analysis was based on alarge RCT, and costing was conducted from a societal perspective. Cost categories included theorlistat acquisition, glucose tolerance test for impaired glucose tolerance (IGT), treatment ofdiabetes, and treatment of obesity. The patients paid the cost of the orlistat, while other costs werepaid by the Italian National Health Service. The study indicated that orlistat plus LCD and exercisewas associated with a cost of $101,564 per QALY gained, compared to LM alone. When orlistat wasgiven only to obese IGT patients, the cost decreased to $28,631per QALY gained. The studyBariatric treatments for adult obesity 165