Variables | Definition | Numerator | Denominator |
---|---|---|---|
Retention | All patients who are not registered as deceased or LTFU for any reason | Number of patients alive and on ART | Number of patients alive and on ART plus death plus LTFU |
Loss to follow-up | Patients who miss scheduled visits to the clinic for more than three months after the last visit | Not applicable (NA) | NA |
Transfer out | It refers to the official transfer of the patient to another clinic | NA | NA |
Transfer in | It refers to the official transfer of the patient from another clinic | NA | NA |
Cumulative retention | The total retention by the end of the calendar among patients ever started on ART | Number of patients alive and on ART by the end of the calendar | The total number of patients ever started on ART |
Current retention | The retention rate during a specific “calendar” among patients who were on ART sometime during the “calendar” | Number of patients alive and on ART by the end of the “calendar” | Number of patients alive and on ART by the end of the calendar plus number of patients who died plus LTFU during the “calendar” |
Calendar | The time during which the level of the “current retention” is estimated | NA | NA |