Seasonality in the adverse outcomes in weight loss surgeries

Weight loss surgery is a common procedure in the United States.

As weight loss surgery is largely an elective procedure for which patients and physicians can choose the timing, it could be helpful to explore the seasonality pattern of its perioperative adverse outcomes to help decide the timing of this surgery.

United States.

We used an obese adult sample (age ≥20 yr) of patients who underwent weight loss surgeries from the Premier Healthcare Database from 2011 to 2014. The International Classification of Diseases, Ninth Revision Clinical Modification procedure codes were used to identify weight loss surgery cases. Binary variables are used for 4 adverse outcomes, including hospital mortality, sepsis, deep vein thrombosis (DVT), and pulmonary embolism. The associations between the adverse outcomes and season of surgery were examined using logistic regressions, adjusting for age, sex, race, marital status, surgery types, body mass index, the Charlson co-morbidity index, and region.

A total of 69,365 weight loss surgeries were identified for the analytic sample. The overall rate was .27% for hospital mortality, .16% for DVT, .10% for pulmonary embolism, and .20% for sepsis. For DVT, adjusted odds ratio for the fall was 2.68 (95% confidence interval: 1.39-5.19) and the odds ratio for the winter was 2.26 (95% confidence interval: 1.09-4.27) compared with the summer. For sepsis, adjusted odds ratio for the spring was 1.83 (95% confidence interval: 1.07-3.12) compared with that of the summer. The seasonality pattern was not statistically significant for hospital mortality and pulmonary embolism.

DVT and sepsis are more likely to occur in colder seasons compared with the summer season, although the crude rates of these adverse events were low.