title: A validation of an intelligent decision-making support system for the nutrition diagnosis of bariatric surgery patients.
abstract: BACKGROUND
  Bariatric surgery is an important method for treatment of morbid obesity. It is known that significant nutritional deficiencies might occur after surgery, such as, calorie-protein malnutrition, iron deficiency anemia, and lack of vitamin B12, thiamine, and folic acid.
  
  
  OBJECTIVE
  The objective of our study was to validate a computerized intelligent decision support system that suggests nutritional diagnoses of patients submitted to bariatric surgery.
  
  
  METHODS
  There were fifteen clinical cases that were developed and sent to three dietitians in order to evaluate and define a nutritional diagnosis. After this step, the cases were sent to four bariatric surgery expert dietitians who were aiming to collaborate on a gold standard. The nutritional diagnosis was to be defined individually, and any disagreements were solved through a consensus. The final result was used as the gold standard. Bayesian networks were used to implement the system, and database training was done with Shell Netica. For the system validation, a similar answer rate was calculated, as well as the specificity and sensibility. Receiver operating characteristic (ROC) curves were projected to each nutritional diagnosis.
  
  
  RESULTS
  Among the four experts, the rate of similar answers found was 80% (48/60) to 93% (56/60), depending on the nutritional diagnosis. The rate of similar answers of the system, compared to the gold standard, was 100% (60/60). The system sensibility and specificity were 95.0%. The ROC curves projection showed that the system was able to represent the expert knowledge (gold standard), and to help them in their daily tasks.
  
  
  CONCLUSIONS
  The system that was developed was validated to be used by health care professionals for decision-making support in their nutritional diagnosis of patients submitted to bariatric surgery.
authors.affiliation: Pontifical Catholic University of Paraná (PUCPR), Curitiba, Brazil. nutriclinmagda@bol.com.br.
authors.forename: Magda Rr
authors.initials: MR
authors.lastname: Cruz
authors.forename: Cristina
authors.initials: C
authors.lastname: Martins
authors.forename: João
authors.initials: J
authors.lastname: Dias
authors.forename: José S
authors.initials: JS
authors.lastname: Pinto
keywords: Bayesian networks; artificial intelligence; bariatric surgery; decision-making; nutrition diagnosis; support system