Bariatric treatments for adult obesity - Institute of Health Economics

DiscussionThe objectives of the economic analysis were:to determine the comparative cost-effectiveness of various bariatric treatment strategies forobesity in adults;to assess the economic burden of obesity in Alberta; to estimate the direct health services cost associated with bariatric surgery.Four types of bariatric interventions were identified in the literature review. These include bariatricsurgical procedures, pharmacotherapy, lifestyle modification, and weight management programs.The CADTH report constructed a Markov model to evaluate the cost-effectiveness of bariatricsurgery versus lifestyle modification or other bariatric surgical intervention for patients with a BMI≥ 40 kg/m 2 or a BMI ≥ 35 kg/m 2 with obesity-related comorbidities. This model applied clinicalevidence based on a systematic review and cost data collected from the provinces of Alberta andOntario and, therefore, can be generalized to an Alberta context. The model demonstrated thatbariatric surgery is cost-effective for patients with severe obesity, compared to lifestyle modification.Compared to lifestyle modification, the lifetime cost per QALY gained was $9398 for RYGB and$12,212 for LAGB. Moreover, surgery was particularly cost-effective for patients with obesityrelatedcomorbidities. However, within bariatric surgical interventions, due to limitations in the dataavailable for analysis, the most effective type of bariatric surgery could not be identified.For studies that evaluated bariatric surgical procedures in comparison with lifestyle modification,bariatric surgery was demonstrated to be cost-effective for patients with a BMI ≥ 40 kg/m 2 or aBMI ≥ 35 kg/m 2 with obesity-related comorbidity. Results from the CADTH review 1 of theeconomic literature indicated that bariatric surgery was associated with a cost per QALY gained of$5000 to $40,000. Furthermore, there is evidence to indicate that the surgery is more cost-effectivefor obesity patients with T2DM. 4,7,13 Still, within bariatric surgical procedures, it is uncertain from theliterature which bariatric surgery is the most cost-effective.For studies that evaluated pharmacotherapy in comparison with no intervention, lifestylemodification or WMP, the pharmacotherapy was associated with the improvement in health benefitfor treating patients with a BMI ≥ 30 kg/m 2 or a BMI ≥ 27 kg/m 2 with T2DM. However, the costeffectivenessof the comparisons varied, depended upon the specific medical conditions andinterventions being evaluated.For orlistat, as compared to no intervention, the cost per QALY gained was less than $18,881 forpatients with T2DM; and compared with lifestyle modification, the cost per QALY gained was$28,631 for patients with impaired glucose tolerance (IGT). This suggested that orlistat treatment forobese patients with obesity-related morbidity was cost-effective. For the treatment of obese patientswithout obesity-related morbidity, and in comparison with LM alone, one study showed that orlistatplus LM was cost-effective 15 but three studies showed that the medication generated its healthbenefits at a greater cost, and therefore was less cost-effective. 14,16,21Of the studies evaluating sibutramine, three studies showed that, as compared to LM alone, the costper QALY gained, plus LM, was less than $18,486, suggesting the medication was cost-effective. 18-20By contrast, one study showed that the cost per QALY gained for sibutramine plus LM was $75,255as compared to LM alone, and $55,349 as compared to no intervention, suggesting the medicationwas not cost-effective. 17 Moreover, as compared to WMP, one study showed that sibutramine plusWMP generated a significant weight loss, but at no cost savings. 24Bariatric treatments for adult obesity 174