Cost-effectiveness analysis of laparoscopic gastric bypass, adjustable gastric banding, and nonoperative weight loss interventions

Abstract

Background: Laparoscopic adjustable gastric banding (LAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGB) are the two most commonly performed bariatric procedures. Although both procedures likely reduce healthcare expenditures related to the resolution of co-morbid conditions, they have different rates of perioperative risks and different rates of associated weight loss. We designed a model to evaluate the incremental cost-effectiveness of these procedures compared with nonoperative weight loss interventions and with each other.

Methods: We used a deterministic, payer-perspective model comparing the lifetime expected costs and outcomes of LAGB, LRYGB, and nonoperative treatment. The major endpoints were survival, health-related quality of life, and weight loss. Life expectancy and lifetime medical costs were calculated across age, gender, and body mass index (BMI) strata using previously published data.

Results: For both men and women, LRYGB and LAGB were cost-effective at <$25,000/quality-adjusted life-year (QALY) even when evaluating the full range of baseline BMI and estimates of adverse outcomes, weight loss, and costs. For base-case scenarios in men (age 35 y, BMI 40 kg/m(2)), the incremental cost-effectiveness was $11,604/QALY for LAGB compared with $18,543/QALY for LRYGB. For base-case scenarios in women (age 35 y, BMI 40 kg/m(2)), the incremental cost-effectiveness was $8878/QALY for LAGB compared with $14,680/QALY for LRYGB.

Conclusion: The modeled cost-effectiveness analysis showed that both operative interventions for morbid obesity, LAGB and RYGB, were cost-effective at <$25,000 and that LAGB was more cost-effective than RYGB for all base-case scenarios.

Figure 1. Deterministic decision analytic model of 3 year operative and non-operative interventions for morbid obesity

The square represents a decision node, the circles represent probability nodes and the triangles represent end nodes. The text above the lines describes the clinical event and the percentage under it represents the probability of the event.

Figure 2. One-way sensitivity analysis

One-way sensitivity analysis of the difference in incremental cost-effectiveness ratio (ICER) between the strategies of LRYGB and LABG for 45 year old female patients with BMI 40 kg/m². The dashed vertical line represents the difference between the ICER for LRYGB and LAGB using the base-case values. The solid lines demonstrate the impact on ICER of the variables.

Figure 3. Two-way sensitivity analysis of cost-effectiveness of LAGB and LRYGB

The diagram depicts the difference in the cost-effectiveness between LAGB and LRYGB with varying percentage of excess body weight loss (EBWL) achieved with these procedures, for 45-year-old women with BMI of 40. The shaded area represents EBWL values for which the difference in the cost-effectiveness of the surgical procedures favors LAGB. The line depicts scenarios where of LAGB and LRYGB yield the same cost-effectiveness. The cross represents the difference in the cost-effectiveness of these procedures using the base-case estimates