Fig. 1

Time Line for Packaged Intervention. The first observation period, Study Implementation, began in January 2014, 6 months before initiation (yellow line) of the KwaZulu-Natal HIV Drug Resistance Surveillance Study (DReSS) and ended in December 2014 prior to when participants were due for their first HIV-1 viral load (first red dashed line). During this period, DReSS nurses assisted with clinic blood draws and maintained the study participant clinic files in a secure location. The second observation period, Study Steady State, began in January 2015 and ended in June 2015 (second red dashed line). Outreach phone calls and visits began during this period to assist in obtaining blood samples for viral loads. The final observation period, Chart Intervention, began in July 2015 at the time of the first chart audit (green bar) and ended in July 2017 several months after the second chart audit (yellow bar). This period included improvements in chart documentation and the introduction of the viral load register. DReSS completed the final follow up visit in July 2018 (blue line)