Bariatric treatments for adult obesity - Institute of Health Economics

etween surgical interventions, the cost per QALY gained was $673 for sleeve versus LAGB and$10,714 for BPD versus RYGB. Furthermore, RYGB was less effective and more costly comparedto sleeve (that is, sleeve dominated RYGB). At 10 years, 20 years, and lifetime, compared to LM, thecost per QALY gained was $21,595, $13,674, and $9398, respectively, for RYGB; and $37,910,$21,240 and $12,212, respectively, for LAGB. Furthermore, when the proportion of patients withobesity-related morbidity was increased, compared to LM, the cost per QALY gained for RYGBdecreased. The study concluded that bariatric surgeries were more cost-effective than lifestylemodification for the treatment of patients with severe obesity. However, within surgicalinterventions, it was uncertain which surgical intervention had the greatest cost-effectiveness due tolimitations in available data.Anselmino et al. 4 used a decision analytic model to evaluate the cost-effectiveness of adjustablegastric banding (AGB) and gastric bypass procedures (GBP) compared to medically guided diet(conventional treatment) for treating obese patients (BMI ≥ 35 kg/m 2 ) with type 2 diabetes (T2DM).The study was conducted from a payer’s perspective over a 5-year time horizon in three Europeancountries (Austria, Italy, and Spain) and included the cost of pre-surgery assessment, surgicalprocedures, hospitalization, follow-up, physician visits, and the treatment for surgery-relatedcomplications and T2DM. In Austria and Italy, AGB and GBP were less costly and more effectivethan conventional treatment (CT) (that is, they dominated CT). In Spain, compared to CT, the costper QALY gained was $1964 3 for AGB and $3593 for GBP. The study concluded that compared toCT, AGB and GBP were cost-effective interventions for the treatment of severely obese patients.Summary of CADTH reportNine studies 5-13 were already reviewed by the CADTH report and are summarized below. Thestudies assessed the cost-effectiveness of a bariatric surgery in comparison with either anothersurgical alternative or standard care for patients with a BMI ≥ 40 kg/m 2 or a BMI ≥ 35 kg/m 2 withobesity-related morbidity. The majority of these studies took a payer’s perspective; three 8,9,11 took asocietal perspective.For studies that evaluated surgical interventions versus standard care, the cost per QALY gainedranged between $5000 and $40,000, indicating the bariatric surgical interventions were cost-effective.Craig et al. 10 reported the cost-effectiveness ratios for GBP by age groups; they ranged from $5646to $16,834 for women and $11,188 to $37,223 for men. Surgery was the least cost-effective forelderly patients. In the study by Salem et al., 6 RYGB was associated with a cost less than $26,140 perQALY gained, as compared to standard care.For obese patients with T2DM, bariatric surgery was found to be more cost-effective than standardcare in two studies. 7,13 Ackroyd et al. 7 reported $2406 per QALY gained for LGBP and $3308 perQALY gained for LAGB in the UK; in France and Germany, the bariatric interventions were moreeffective and less costly. Keating et al. 13 showed that LAGB was associated with a gain of 0.7 lifeyear and 1.2 QALYs at a lower cost ($2614 in savings).For studies that evaluated surgical interventions with other surgical interventions, Paxton et al., 9 vanMastrigt et al., 11 and Clegg et al. 12 provided direct comparisons across bariatric surgical alternatives.Paxton et al. assumed that weight loss was comparable between open gastric bypass andlaparoscopic gastric bypass, and hence conducted a cost-minimization analysis. They reported the3 To facilitate the comparison, all currencies are converted to Canadian dollars using the exchange rates released by theBank of Canada on August 11, 2010.Table E.A.2 for costs in original currencies.Bariatric treatments for adult obesity 164