Study results published in JAMA Surgery explored the association between healthcare expenditures in veterans with obesity who had and had not undergone bariatric surgery. Although the surgery was associated with several quality of life benefits, few studies have charted the effects of bariatric surgery on healthcare expenditures in the years following. The study compared 2498 bariatric surgery patients with severe obesity to 7456 matched patients who did not have the procedure and tracked the healthcare expenditures of both groups up to 10 years post-procedure.
Using data from the Veterans Administration (VA) electronic health record, researchers identified veterans who underwent any bariatric surgery procedure from 2000 to 2011. Potential matches were identified using sequential stratification matching based on age, sex, diabetes diagnosis, race/ethnicity, diagnostic cost group (DCG), and other factors. Ultimately, up to 3 non-surgery patients were matched to each patient who had undergone surgery. Overall, both cohorts were similar in all observed characteristics. The mean age in the surgery group was 52.3±8.8 years and 52±8.7 years. Mean body mass index was 47 and 46, respectively. Most patients were white (81.3%) men (74.2%) who had previously received a diabetes diagnosis and had various comorbidities including hypertension, dyslipidemia, arthritis, gastroesophageal reflux disease, and depression.
During the study, the researchers examined outpatient, inpatient, and outpatient pharmacy expenditures from 3 years pre-surgery to 10 years post-surgery. To estimate VA outpatient pharmacy and inpatient expenditures, researchers used marginalized 2-part models. In all models, patients’ age, body mass index, DCG score, marital status, copayment status, and prevalence of 12 comorbidities were adjusted. Total pre-surgical expenditures were estimated in order to assess their effect on results after surgery, as were total pre-surgical expenditures.
Researchers observed that median bariatric procedure expenditure was lowest for adjustable gastric banding ($15,546) and highest for biliopancreatic diversion ($36,513). The model-estimated pre-surgery expenditure of $3167 at 3 years pre-surgery increased up to 6 months post-surgery, after which they decreased and ultimately increased again by 10 years post-surgery. Compared with the non-surgery group the surgery group had higher total expenditures 3 years pre-surgery. These differences increased until 5.5 years post-surgery and remained lower through 10 years post-surgery. Cumulative expenditures, including inpatient, outpatient, and pharmacy expenditures, 10 years post-surgery indicated that overall the surgery group had higher expenditures ($143,248 spent) than the non-surgery group ($117,378 spent). The researchers explained that the continued high costs of the surgery group are likely due to the fact that surgery did not necessarily cause all patients to experience remission of obesity-related conditions like diabetes and that there are various adverse effects of bariatric surgery that may have required long-term treatment and care.
The researchers noted several study limitations. Patients were not randomized and were not matched on all available characteristics. Pre-surgery expenditure estimates differed between the surgery and non-surgery groups and did not present causal effects but associations. In addition, this study only used data from the VA and did not take other insurance structures into account. Since the study only used data from older male patients, the researchers note that the results may not be generalizable to other demographics such as female, younger, or non-veteran patients.
Since bariatric surgery was not associated with lower healthcare expenditures the researchers suggest that the value of the surgery is its potential to provide patients with a higher quality of life through various health improvements rather than decreasing healthcare costs. They do, however, suggest that surgery may be more cost-effective for younger patients and patients with fewer comorbidities. Future studies could help understand the association between age, disease severity, and cost-effectiveness for the surgeries. as well as whether newer bariatric procedures have greater potential for cost-effectiveness.
Smith VA, Arterburn DE, Berkowitz TSZ, et al. Association between bariatric surgery and long-term health care expenditures among veterans with severe obesity [published online October 30, 2019]. JAMA Surg. doi:https://doi.org/10.1001/jamasurg.2019.3732.