Comparative Analysis of Mortality Rates Among Morbidly Obese Individuals: A Study of Patients Undergoing Bariatric Surgery, Non-surgical Morbidly Obese Individuals, and the General Population.

Abstract

Mortality decrease following bariatric surgery. We explored the extent of the reduction and whether or not it reaches the general population level in a large cohort of patients with obesity. Compare all-cause mortality between patients with obesity who undergo bariatric surgery and those who do not, with the general Iranian population during the same period. Data from Iran's National Obesity Surgery Database was used to establish a large cohort of patients registered between 2009 and 2019. The current vital status of the patients was determined by utilizing post-surgery follow-up data for those who underwent the operation. For patients without a surgery record, a predefined checklist was filled out through telephone interviews. Death data from the National General Registrar's office was obtained for all cohort members. Of 13313 cohort members, 12915 were eligible for analysis. The median age at the first visit was 38 years, and 78% were women. 6190 patients (47.9%) underwent bariatric surgery, and 6725 patients (52.1%) were not yet operated on at the time of analysis. We observed 139 deaths during 53,880 person-years (PY) follow-ups. The median follow-up for operated-on and not-operated-on groups were 4 and 4.8 years. The mortality rates among non-operated patients were 2.89 times higher (SMR=2.89, 95% CI: 2.36-3.53) than those in the general population, while in operated patients, the mortality rate decreased to 1.82 as high (SMR=1.82, 95% CI: 1.34-2.46). The risk of death has been diminished in the operated-on group. It still remains considerably higher than the risk in the general population.