Fig. 1

a. Determining the prescription duration time period. The prescription duration period for each antiretroviral was defined as the time from the date the first prescription was filled to the date the last prescription was filled. If there was any gap of 250 days or more between prescription purchases, the first prescription duration period was defined as ending on the date of the last prescription purchase, and the next prescription duration period was defined as starting on the date of the next prescription purchase. b Determining the patient’s most recent ART regimen. Prescription durations were determined for individual drugs and tested for overlap. The patient’s regimen was defined as the overlapping combination of drugs that was last dispensed in the 2016 calendar year