By Nancy Walsh, Staff Writer, MedPage Today

Action Points

Obese patients who underwent bariatric surgery had greater healthcare utilization during the first years after the procedure, but this leveled off over time and medication costs eventually were significantly lower than for patients who had not had the surgery, a Swedish study found.

During the first 6 years postsurgery, patients spent an annual mean of 1.7 days in the hospital compared with 1.2 days among controls, for an adjusted difference of 0.5 (95% CI 0.2 to 0.7, P<0.001) days, according to Martin Neovius, PhD, of the Karolinska Institute in Stockholm, and colleagues.

However, between years 7 and 20, surgery patients and controls both had an annual 1.8 in-hospital days (P=0.95), the researchers reported in the Sept. 19 Journal of the American Medical Association.

Drug costs were lower among the surgery group during this same period, however. Between years 7 and 20, the mean annual drug price tag for the surgery patients was $930, compared with $1,123 for controls (adjusted difference ?$228, 95% CI ?335 to ?121, P<0.001).

In particular, drug costs were lower for cardiovascular and diabetes treatments, “reflecting the effects of bariatric surgery on diabetes remission, diabetes prevention, and cardiovascular disease events,” the researchers noted.

Many benefits have been established for bariatric surgery among obese individuals, including reductions in rates of cardiovascular disease and diabetes, as well as decreased mortality.

Nonetheless, the long-term effects on healthcare utilization have not been established, so Neovius and colleagues examined data from the Swedish Obese Subjects study, which included 2,010 patients who had bariatric surgery and 2,037 matched controls who were given interventions such as behavior modification and lifestyle guidance.

Available data included hospitalizations beginning 4 years before the surgery through 20 years postsurgery, outpatient visits (other than primary care) between postsurgery years 2 through 20, and drug expenditures between years 7 and 20.

At baseline, patients who had the surgery were heavier and younger and more likely to smoke and have diabetes.

In almost 70% of the surgical patients, the procedure used was vertical-banded gastroplasty.

After 10 years, those who had surgery had lost 17% of their body weight. At years 15 and 20, their weight loss was maintained at 16% and 18%, respectively.

In contrast, controls gained 1% of their body weight by year 10, and lost 1% at years 15 and 20.

During the overall 20-year follow-up, the surgery group accrued 54 total hospital days compared with 40 days among controls, for an adjusted difference of 15 days (95% CI 2 to 27, P=0.03).

A year-by-year analysis determined that the greatest difference in days spent in the hospital among surgery patients was during the first year, at 9.4 versus 0.9 for controls, giving an adjusted difference of 8.4 (95% CI 7.8 to 9.1, P<0.001) days, the researchers reported.

However, the differences declined in the subsequent years, though remaining significant, to 1 (95% CI 0.6 to 1.4, P<0.001) during the second year, 0.4 (95% CI 0.1 to 0.7, P=0.02) during the third year, and 0.5 (95% CI 0.1 to 0.9, P=0.02) in the fourth year.

By the fifth year, differences in in-hospital days no longer were seen.

These increased hospitalizations in the surgery group most likely related to the need for surgical revisions and management of complications, as well as for gallstones and anemia, according to the researchers.

For nonprimary care outpatient visits, the surgery group again had more usage between years 2 and 6, with an adjusted mean difference of 0.3 (95% CI 0.1 to 0.4, P=0.003) visits.

Beginning in year 7, however, no differences were seen (adjusted mean difference ?0.2, 95% CI ?0.4 to 0.1, P=0.12).

The researchers conceded that an overall reduction in healthcare usage was not seen in the study.

Despite the benefits of surgery on chronic disease, “translating these benefits into reduced healthcare resource use may not be evident for many years because these diseases take many years before they become problematic,” they explained.

Limitations of the study included a lack of randomization, no information on primary care outpatient visits, and changes in surgical procedures since the early years of enrollment in the cohort.

From the American Heart Association:

• Bariatric Surgery and Cardiovascular Risk Factors

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