Variation in Visits Classified by GI ICD9 Biosurveillance Sub-Filters as a Function of Age

The CDC recently developed sub-syndromes for classifying disease to enhance syndromic surveillance of natural outbreaks and bioterrorism. They have developed ICD9 classifiers for six GI Illness subsyndromes: Abdominal Pain, Nausea and Vomiting, Diarrhea, Anorexia, Intestinal infections, and Food poisoning. If the number of visits for sub-syndromes varies significantly by age it may impact the design of outbreak detection methods.

Objective

We hypothesized that the percentage of visits for the GI sub-syndromes varied significantly with age.