Linkage to care and in care

 

Why look at patterns in engagement in care, antiretroviral treatment and viral suppression?

  • To maintain and improve health and reduce the risk of new HIV transmissions, it is important for people living with HIV to be diagnosed, in care, on antiretroviral treatment (ART), and virally suppressed (see HIV prevention, engagement and care cascade).
  • Understanding cascade trends can help measure the impact of HIV care and monitor progress toward meeting the UNAIDS 90-90-90 targets.
  • Identifying gaps in the cascade can help the care system prioritize interventions and inform program/policy changes to improve engagement.
  • Although being in care, on ART, and virally suppressed are important for health and well-being, they do not necessarily reflect overall quality of life for a person living with HIV.

 

Where do these data come from?

  • Data in this section comes from the Public Health Ontario Laboratory (PHOL), which conducts centralized HIV diagnostic and viral load (VL) testing for the province.
  • PHOL’s HIV diagnostic and VL databases were combined and used to create a group (also known as a cohort) of people living with diagnosed HIV in Ontario – referred to as the Ontario HIV Laboratory Cohort – whose cascade engagement can be monitored over time. The cohort includes all people in the laboratory databases who have record of a nominal HIV-positive diagnostic test and/or at least one VL test, and have not been administratively lost-to-follow-up (LTFU). For more information on who is and isn’t included in this cohort, go here.
  • All information in the PHOL databases is confidential, and only de-identified aggregate data are shared with OHESI partners.

 

What are some of the limitations of these data?

  • It is assumed that having a single VL test in a given calendar year means that a person is in care, and having no VL test means a person is not in care. This may not reflect an individual’s actual state of engagement in care. For example, a health provider may recommend less frequent VL testing for a patient who has been virally suppressed for several years, which may lead to an underestimate of the number of people in care.
  • While the Ontario HIV Laboratory Cohort represents our best province-wide understanding of the cascade among diagnosed people with HIV in Ontario, it is unclear to what extent the cohort represents all people with an HIV-positive diagnosis who are currently living in the province. Representativeness may be limited by the exclusion of  non-nominal HIV-positive diagnostic tests (although individuals diagnosed non-nominally are included in the cohort when they receive a VL test) and the inability to directly account for deaths and migration out of the province. More information on these limitations can be found here.