Fig. 2

Comparison of the code count trend differences between 996 and 999 and 800–999

The percent deviation from the annual monthly average code count for both the Complications of Surgical Care (996–999) diagnosis family and the broad category of Injury and Poisoning (800–999). By calculating the average monthly code count for each family and the percent deviation per month from that expected average, we see that both code families follow a similar seasonal pattern of increase in the summer and decrease in the winter in terms of raw code count. While they follow the same pattern, Complications of Surgical Care doesn’t decrease as much in the winter, and actually has a spike in December, which is why our method picks up this diagnosis family as enriched in the winter. Since the number of trauma visits is used to establish a baseline expected rate of each code count, our method is detecting relative enrichment and not absolute enrichment