Patient selection: type 2 ethnic Chinese 18-67 years of age with type 2 diabetes undergoing bariatric surgery
Outcome: remission from type 2 diabetes at 12 months after gastric bypass surgery (defined as hemoglobin A1c less than 6%)
Parameters:
(1) body mass index in kg per square meter
(2) duration of diabetes in years
(3) fasting C-peptide concentration in ng/mL
X =
= (0.05 * (BMI)) – (2.7 * (duration diabetes)) + (0.38 * (C-peptide concentration)) – 1
odds of diabetes remission =
= EXP(X)
When the equation was used as published, the results seemed unlikely. When it was modified to the following (see equation on page 23) more reliable values were returned.
X =
= (0.05 * (BMI)) – (0.27 * (duration diabetes)) + (0.38 * (C-peptide concentration)) – 1
Alternatively the number of favorable findings could be counted:
(1) body mass index > 35
(2) diabetes duration less than 4 years
(3) fasting C-peptide concentration > 2.9 ng/mL
Performance:
• The presence of >= 2 of the 3 predictors predicted remission with a sensitivity of 82% and specificity of 87%.
• The area under the ROC curve was 0.90 for the equation.
• 84% of study participants were correctly assigned.
