Metabolic bariatric surgery is a cost-effective intervention among individuals with obesity without any comorbidities

Metabolic bariatric surgery (MBS) is a cost-effective intervention among individuals with obesity (BMI > 40 kg/m2) without any comorbidities from the healthcare system and societal perspectives, in the context of the Saudi Arabia, according to researchers from King Fahad Medical City, Riyadh, Saudi Arabia.

This study revealed that MBS is a cost-effective strategy in the Saudi Arabia, considering a willingness-to-pay (WTP) threshold of three GDP per capita per quality-adjusted life years (QALY), US$ 91,308 (SAR 342,405; PPP 182,324) from both healthcare system and societal perspectives. These findings are in line with several previous studies conducted in other countries, which reported that MBS is a cost-effective or even cost-saving intervention among patients with severe obesity (BMI ≥ 40 kg/m²).

However, the researchers caution that it is important to note that many of these earlier studies analysed the cost-effectiveness of MBS among a specific population or among patients with individual comorbidities, concluding that MBS was a cost-effective strategy among people living with obesity and different comorbidities.

The investigators used a Markov model to estimate the lifetime costs and outcomes of MBS. Costs and outcomes were discounted at an annual rate of 3%. The analysis was conducted from societal and healthcare system perspectives, using a willingness-to-pay (WTP) threshold of one to three times the gross domestic product (GDP) per capita per quality-adjusted life years (QALY) gained. Direct medical and nonmedical costs were obtained from hospital records and patient surveys, respectively. Transitional probabilities and utility values were obtained from published literature and primary data collection in the KSA. One-way and probabilistic sensitivity analyses were performed to assess parameter uncertainty.

All costs were reported in 2022 values in SAR and then converted to US$ and PPP based on the 2022 official exchange rates. One US$ equals 3.75 SAR, whereas one PPP equals 1.878 SAR.49,50

The findings of this study were total costs, life years, (QALY), and the incremental cost-effectiveness ratio (ICER). The ICER was calculated in SAR, US dollars, and PPP. An ICER lower than one GDP per capita is considered very cost-effective, an ICER of one GDP per capita to less than three GDP per capita is considered cost-effective, and an ICER higher than three GDP per capita is not cost-effective.

Outcomes

From a societal perspective, MBS costs US$ 148,512 (SAR 556,922; PPP 296,550) and yields 6.720 LY and 4.968 QALY, whereas the standard treatment costs US$ 136,538 (SAR 512,016; PPP 272,639) and yields 6.316 LY and 4.593 QALY, giving an ICER of US$ 29,668 (SAR 111,256; PPP 59,242) per LY saved and US$ 31,909 (SAR 119,660; PPP 63,717) per QALY gained. Considering a healthcare system perspective, the ICER was US$ 33,800 (SAR 126,749; PPP 67,492) per LY saved and US$ 36,353 (SAR 136,324; PPP 72,590) per QALY gained.

Based on the one-way sensitivity analysis, the five most significant parameters that affected the ICER value were the discounting rate for costs, discounting rate for outcomes, direct medical costs associated with MBS, direct medical cost of cancer, and direct medical costs associated with standard treatment, as presented in the Tornado diagram (Figure 1).

Figure 1: Tornado diagram of one-way sensitivity analysis (Abbreviations: ICER, Incremental cost-effectiveness ratio; LL, Lower limit; QALY, Quality-adjusted life year; UL, Upper limit)

From a societal perspective, at the WTP threshold of one GDP per capita per QALY, US$ 30,436 (SAR 114,135; PPP 60,775), the standard treatment had a 63% probability of being cost-effective and MBS had a 37%. Meanwhile, at the WTP threshold of approximately 1.8 GDP per capita per QALY, US$ 56,000 (SAR 210,000; PPP 111,821), MBS was more cost-effective than the standard treatment in 100% of the iterations.

“To guide sustainable policy decisions, it is crucial to establish a cost-effectiveness threshold that reflects the structure of the local healthcare system, national priorities, and societal values. Additionally, evaluating the cost-effectiveness of MBS in patients with different comorbidities can help prioritize interventions and optimize resource allocation,” the researchers concluded. “Finally, the development of national registries to track surgical outcomes, wait times, and costs will enable continuous policy refinement and improve the overall healthcare system performance.”

The findings were reported in the paper, ' Cost-Utility Analysis of Metabolic Bariatric Surgery for Individuals with Obesity in Saudi Arabia', published in Dovepress. To access this paper, please click here