Selected 2012 WHO Early Warning Indicator Definitions (Numerator/Denominator) and Targets.

ART – Antiretroviral therapy.
ARV – Antiretrovirals.
*On-time pill pick-up: Pick up pills no more than two days late on their first pick-up after a baseline pick-up.
§EWI sample start date: The date designated as the start of the sampling. The sample start date is fixed by the HIVDR Working Group.
†Lost to follow-up: Patients who had not returned to the pharmacy or clinic ≤90 days after the last ART run-out date during the 12-months after the date of ART initiation were classified as LTFU. Stopping therapy without restarting was classified as not LTFU if the patient continued to attend clinic appointments.
∞Transfers of care to another site were excluded from the denominator.
‡Stock-out: Any occurrence of zero stock of a routinely-used ARV drug at the site at which the patient routinely picks up ARVs.
#Adult and pediatric targets are the same. Targets for Virological Suppression at 6-months have not been determined by WHO.
∧Due to routine data collection of viral load at 6 months, Namibia chose to monitor Virological suppression at 6 months instead of the WHO recommendation of 12 months.
Table adapted from WHO HIV Drug Resistance EWI guidance report [4].