The following chart, based on a study of over 20,000,000 patients’ records in Practice Velocity’s database of patient visits across the United States, illustrates the frequency of influenza diagnoses between January 2010 and October 2016 relative to total urgent care visits that carried an evaluation and management (E/M) code. The period of December through January is the typical peak of the flu season, although in some years flu outbreaks occur somewhat earlier or later. In 2016, for instance, there was a low incidence of flu until March. Some years have a “double hump” flu season, meaning that the number of flu cases increases in both December and March. Generally, though, flu peaks only once, in either December or March.
Flu as a percentage of total visits