A scoring system for clinical assessment of mortality risk has been previously proposed for bariatric surgery.
The Obesity Surgery Mortality Risk Score (OS-MRS) was developed from a single institution experience of 2075 patients.
Dr DeMaria and colleagues provide multicenter validation of the value of the Obesity Surgery Mortality Risk Score.
|Mortality was 5-fold greater in the intermediate vs lowest risk group|
|Annals of Surgery|
The Obesity Surgery Mortality Risk Score assigns 1 point to each of 5 preoperative variables, including a body mass index of 50 kg/m2 or more.
Male gender, hypertension, known risk factors for pulmonary embolism, and age over 45 years are also variables taken into account by the score.
Patients with total scores of 0 to 1 are classified as lowest risk, scores 2 to 3 as intermediate, and scores 4 to 5 as high risk.
The team collected data from 4431 consecutive patients undergoing a primary gastric bypass at 4 bariatric programs recruited to validate the proposed system.
The research team analyzed Obesity Surgery Mortality Risk Score as a means of stratifying surgical mortality risk.
The researchers found there were 33 total deaths for an overall mortality for the validation cohort of 1% consistent with published standards.
Mortality for 2164 lowest risk patients was 0.2%, and for 2142 intermediate risk patients it was 1%.
For 125 high risk patients, mortality was 2%.
The researchers noted that mortality was significantly different between each of the 3 risk groupings.
The team found mortality was 5-fold greater in the intermediate risk group than in the lowest risk group.
Only 6 patients with all 5 risk factors were identified.
The team observed that high risk patients were characterized by a 12-fold greater mortality than the lowest risk group, and a disproportionate 9% of all mortalities.
Dr DeMaria's team concluded, "The Obesity Surgery Mortality Risk Score was found to stratify mortality risk in 4431 patients from 4 validation centers that were nonparticipants in the original defining cohort study."
"The score represents the first validated scoring system for risk stratification in bariatric surgery and is anticipated to aid informed consent discussions, guide surgical decision-making, and allow standardization of outcome comparisons between treatment centers."