The HIV treatment cascade (also called the cascade of care or the continuum of care) has become a useful tool to determine how a jurisdiction is doing at diagnosing HIV, linking people living with HIV to care, keeping them in care, starting them on treatment and helping them achieve an undetectable viral load.
Recently, researchers in British Columbia took a closer look at their HIV treatment cascade and found differences among people living with HIV depending on their age, gender, location and risk category. The study<a id="footnoteref1_i4zilyu" title="Lourenço L, Colley G, Nosyk B, et al. High levels of heterogeneity in the HIV cascade of care across different population subgroups in British Columbia, Canada. Paraskevis D, editor. PLoS ONE. 2014;Dec 26;9(12):e115277." ="#footnote1_i4zilyu"="">1 focused on the 2011 calendar year and analyzed linked datasets to look at the number of people living with HIV at each stage of the cascade. The five stages of the cascade were:
- Linkage to care
- Retention in care
- HIV treatment
- Undetectable viral load
In the overall cascade in 2011:
- 7,621 people were diagnosed with HIV
- 96% (7,299) of people diagnosed were linked to care
- 87% (6,348) of linked individuals were retained in care
- 91% (5,754) of people retained in care were on HIV treatment
- 85% (4,862) of people on HIV treatment had an undetectable viral load.
Taking a closer look at the cascade showed that women experience more attrition along the cascade compared to men:
- 11% of men versus 20% of women were lost between linkage to care and retention in care
- 8% of men versus 15% of women were lost between retention in care and on HIV treatment
- 13% of men versus 27% of women were lost between HIV treatment and undetectability
When age was examined, loss across the cascade increased as people living with HIV got younger. For example, people under 30 years old had the greatest attrition across the cascade:
- 25% were lost between linkage to care and retention in care
- 23% were lost between retention in care and on HIV treatment
- 27% were lost between HIV treatment and undetectability
In comparison, people over 50 years of age had the least attrition across the cascade:
- 11% were lost between linkage to care and retention in care
- 5% were lost between retention in care and on HIV treatment
- 11% were lost between HIV treatment and undetectability
When risk category was examined, men who have sex with me (MSM) experienced the least attrition across the cascade while heterosexuals and people who use injection drugs had the greatest attrition. In the transition between linkage to care and retention in care 11% of heterosexuals, 14% of people who use drugs and 6% of MSM were lost. In the transition between HIV treatment and undetectability 15% of heterosexuals, 27% of people who use injection drugs and 8% of MSM were lost.
When the data was divided among the five health authorities, the researchers found that the Northern Health Authority experienced the most loss across the cascade and Vancouver Coastal Health Authority experienced the least.
What Does This Mean for HIV Services?
Although British Columbia's overall treatment cascade approaches the UNAIDS 90-90-90 targets for treating people living with HIV and achieving viral suppression, taking a closer look at the cascade shows that women, youth, people who use injection drugs and people living in northern BC are not optimally engaged in care. Establishing or strengthening routine and targeted HIV testing services, and programs and services that improve retention in care and adherence to treatment for these groups, such as health navigation and multidisciplinary care, may help all people living with HIV access the benefits of care and treatment.
Logan Broeckaert holds a Master's degree in History and is currently a researcher/writer at CATIE. Before joining CATIE, Logan worked on provincial and national research and knowledge exchange projects for the Canadian AIDS Society and the Ontario Public Health Association.
- Lourenço L, Colley G, Nosyk B, et al. High levels of heterogeneity in the HIV cascade of care across different population subgroups in British Columbia, Canada. Paraskevis D, editor. PLoS ONE. 2014;Dec 26;9(12):e115277.