HIV Treatment: Survival After 12 Months on Antiretroviral Therapy

Export Indicator

Percentage of adults and children with HIV known to be on treatment 12 months after initiation of antiretroviral therapy
What it measures

To assess progress in increasing survival among infected adults and children by maintaining them on antiretroviral therapy.

Rationale

One of the goals of any antiretroviral therapy programme is to increase survival among infected individuals. As provision of antiretroviral therapy is scaled up in countries around the world, it is also important to understand why and how many people drop out of treatment programmes. These data can be used to demonstrate the effectiveness of those programmes and highlight obstacles to expanding and improving them.
 
 

Numerator

Number of adults and children who are still alive and on antiretroviral therapy at 12 months after initiating treatment

Denominator

Total number of adults and children who initiated antiretroviral therapy who were expected to achieve 12-month outcomes within the reporting period, including those who have died since starting
therapy, those who have stopped therapy, and those recorded as lost to follow-up at month 12.

Calculation

Numerator / Denominator

Method of measurement

Antiretroviral therapy registers and antiretroviral therapy cohort analysis report form

The reporting period is defined as any continuous 12-month period that has ended within a pre-defined number of months from the submission of the report. The pre-defined number of months can
be determined by national reporting requirements. If the reporting period is 1 January to 31 December 2009, countries will calculate this indicator by using all patients who started antiretroviral therapy any
time during the 12-month period from 1 January to 31 December 2008. If the reporting period is 1 July 2008 to 30 June 2009, countries will include patients who started antiretroviral therapy from 1 July
2007 to 30 June 2008.

A 12-month outcome is defined as the outcome (i.e., whether the patient is still alive and on antiretroviral therapy, dead or lost to follow-up) at 12 months after starting therapy. For example, patients
who started antiretroviral therapy during the 12-month period from 1 January to 31 December 2007 will have reached their 12-month outcomes for the reporting period of 1 January to 31 December 2008.

Measurement frequency

Continuously

Disaggregation

Age group: (greater than) 15 years

Condom type: N/A

Education: N/A

Gender: Male, Female

Geographic location: N/A

HIV status: N/A

Pregnancy status: N/A

Sector: N/A

Service Type: N/A

Target: N/A

Time period: N/A

Type of orphan: N/A

Vulnerability status: N/A

Explanation of the numerator

Explanation of the numerator:

The numerator requires that adult and child patients must be alive and on antiretroviral therapy at 12 months after their initiation of treatment. For a comprehensive understanding of survival, the following data must be collected:
http://www.unaids.org/en/HIV_data/Methodology/default.asp Number of adults and children in the antiretroviral therapy start-up groups initiating therapy at least 12 months prior to the end of the
reporting period;
• Number of adults and children still alive and on antiretroviral therapy at 12 months after initiating treatment.
The numerator does not require patients to have been on antiretroviral therapy continuously for the 12-month period. Patients who may have missed one or two appointments or drug pick-ups, and temporarily stopped treatment during the 12 months since initiating treatment but are recorded as still being on treatment at month 12 are included in the numerator. On the contrary, those patients who have died, stopped treatment or been lost to follow-up at 12 months since starting treatment are not included in the numerator.

For example, for those patients who started antiretroviral therapy in May 2005, if at any point during the period May 2005 to May 2006 these patients die, are lost to follow-up (and do not return), or stop
treatment (and do not restart), then at month 12 (May 2006), they are not on antiretroviral therapy, and not included in the numerator. Conversely, a patient who started antiretroviral therapy in May 2005
and who missed an appointment in June 2005, but is recorded as on antiretroviral therapy in May 2006 (at month 12) is on antiretroviral therapy and will be included in the numerator. What is important is
that the patient who has started antiretroviral therapy in May 2005 is recorded as being alive and on therapy after 12 months, regardless of what happens from May 2005 to May 2006.

Explanation of the denominator

Explanation of denominator:

The denominator is the total number of adults and children in the antiretroviral therapy start-up groups who initiated therapy at any point during the 12 months prior to the beginning of the reporting period,
regardless of their 12-month outcome. For example, for the reporting period 1 January to 31 December 2007, this will include all patients who started antiretroviral therapy during the 12-month period from
1 January to 31 December 2006. This includes all patients, both those on antiretroviral therapy as well as those who are dead, have stopped treatment or are lost to follow-up at month 12.

At the facility level, the number of adults and children on antiretroviral therapy at 12 months includes patients who have transferred in at any point from initiation of treatment to the end of the 12-month period
and excludes patients who have transferred out during this same period to refl ect the net current cohort at each facility. In other words, at the facility level, patients who have transferred out will not be counted
either in the numerator or the denominator. Similarly, patients who have transferred in will be counted in both the numerator and denominator.

At the national level, the number of transferred-in patients should match the number of transferred-out patients. Therefore, the net current cohort (the patients whose outcomes the facility is currently
responsible for recording—the number of patients in the start-up group plus any transfers in, minus any transfers out) at 12 months should equal the number in the start-up cohort group 12 months prior.

Strengths and weaknesses

Using this denominator may underestimate true “survival”, since a proportion of those lost to follow-up
are alive. The number of people alive and on antiretroviral therapy (i.e. retention on antiretroviral therapy)
in a treatment cohort is captured here.

Priority reporting is for aggregate survival reporting. If comprehensive cohort patient registries are
available then it is encouraged for countries to track retention on treatment at 24, 36, and 48 months
and yearly thereafter. This will enable comparison over time of survival on antiretroviral therapy. As it
stands, it is possible to identify whether survival at 12 months increases or decreases over time. However, it is not possible to attribute cause to these changes. For example, if survival at 12 months increases over time, this may reflect an improvement in care and treatment practices or earlier initiation of antiretroviral therapy. The retention on antiretroviral therapy at 12 months therefore needs to be interpreted in view of the baseline characteristics of the cohort of patients at the start of antiretroviral therapy: mortality will be higher in sites where patients accessed antiretroviral therapy at a later stage of infection. Therefore, collection and reporting of survival over longer durations of treatment outcomes may provide a better picture of the long-term effectiveness of antiretroviral therapy.

Further information