Table 1.

Interpretation of events in the mathematical model.

Event	Interpretation
Official transfer out, recorded	Patient transfers to another clinic, and transfer is recorded in the health passport and the clinic records.
Official transfer out, unrecorded	Patient transfers to another clinic, and transfer is recorded in patient's health passport but not in the clinic records.
Self-transfer out	Patient transfers to another clinic without informing the original clinic.
Irregular ART	Patient takes ART (with or without gaps) but does not receive antiretroviral drugs from official clinics.
ART discontinuation, recorded	Patient discontinues ART by clinician's recommendation, and this is recorded in the clinic's records.
ART discontinuation, unrecorded	Patient discontinues ART without informing the clinic.
Death, recorded	Patient dies and the clinic is informed about the death.
Death, unrecorded	Patient dies, but the clinic is not informed about the death.

The events listed in this table correspond to the events presented in Figure 1. See Table S1 (Supplemental Digital Content) for the corresponding list of events in the dataset.