Almost 1 in 5 people in Switzerland disconnected from HIV care over 10 years: only half reconnected and with advanced infection

22 January 2025. Related: Special reports, Treatment strategies.

Simon Collins, HIV i-Base

New research from the Swiss HIV Cohort Study (SHCS) includes clinical outcomes from people living with HIV who disconnected from HIV care for >14 months in this high-income country, often interrupting ART, and often re-engaging with care with advanced HIV. [1]

The paper challenges the approach to HIV surveillance data that censors people who disconnect from care and looked at how to capture silent transfers when people continue to access care but at a different clinic. The analysis used a viral load threshold of 100 copies/mL to categorise whether ART had been interrupted or accessed at a different clinic.

This analysis included 14,864 eligible participants from approximately 21,000 people in the SHCS since 1996. During a median follow-up of 10.2 years (IQR: 4.7 to 17.2), 2768 (18%) people disconnected from care for >14 months, just over half of whom (1489/2768, 53%) re-engaged. Among those who reengaged, 62% had interrupted ART.

Demographic cohort data include 72% male, 28% men (no data on transgender status) with 78% European and 13% African background. Approximately 42% were gay or bisexual men, 37% heterosexual and 16% likely became HIV positive from injecting drug use. Educational status included 30% higher education and 40% vocational training, with 17% having completed school.

The mean CD4 count declined from 374 cells/mm3 (95% CI: 358 to 391) before leaving care to 250 cells/mm3 (95% CI: 221 to 281) among those re-engaging after 14 months and to 185 cells/mm3 (95% CI: 160 to 212) among those re-engaging after 60 months. 

In adjusted analyses (Hazard Ratio, 95%CI), people who interrupted care were less likely to be women HR:0.85 (0.79 to 0.93) and more likely to be heterosexual HR 1.37 (1.23 to 1.52), African 1.36 (1.21 to 1.53), have a history of injecting drugs 2.77 (2.5 to 3.07) and to have only had school eduction 1.21 (1.09 to1.36). Rates of discontinuation increased from 5% after 2 years to 18% after 10 years but decreased over calendar time with highest rates before 2005. Mortality rates were 10% after 10 years and 18% after 20 years.

Among people who interrupted ART during the interruption of care, 12% reengaged with a new CDC stage C diagnosis: 7% vs 17% if reengaging with 14 vs 60 months.

Although a similar decline in absolute CD4 count of about 170 cells/mm3 after two years was reported irrespective of baseline CD4 count when ART was initially started, the impact of the treatment interruption was far more serious for people who had started ART in more advanced HIV.

People who started ART when their CD4 count was already <200 cells/mm3 dropped from a mean 249 (95%CI: 228 to 271) to 89 (95%CI: 21 to 110). This compared to dropping from a mean of 442 (95%CI: 422 to 463) to 275 (95%CI: 251 to 299) in people who started ART with a higher CD4 count.

Although almost 18% of people disconnected from care the researchers reported this as being low for a high-income country compared to 26%  in Belgium, over 30% in the US and 40% in low- and middle-income countries. [2, 3, 4]

comments

These results should prompt similar analyses from other countries as they affect the interpretation of 95:95:95 goals. This concern has already been reported by UKHSA in the UK where up to 18% of people are perhaps disengaged from HIV care, although a presentation at BHIVA last year suggested the actual rate to be closer to 9%. [5]

Although strategies to reengage people in care [6] were included the paper rightly stressed that almost 1300 people – almost 9% of the overall cohort never reengaged with care. Some of these cases could be explained by migration out of the country.

These data also show that people with lower nadir CD4 count had more serious clinical implications from taking a treatment interruption.

This might be an important consideration for research studies that include analytical treatment interruptions (ATIs) even though these studies include careful monitoring.

References

1. Hass AD et al. Late re-engagement into HIV care among adults in the Swiss HIV Cohort Study, JAIDS Journal of Acquired Immune Deficiency Syndromes ():10.1097/QAI.0000000000003597 January 03 2025. | DOI: 10.1097/QAI.0000000000003597. (3 January 2025)
   https://journals.lww.com/jaids/abstract/9900/late_re_engagement_into_hiv_care_among_adults_in.575.aspx
2. Van Beckhoven D et al. Incidence rate, predictors and outcomes of interruption of HIV care: nationwide results from the Belgian HIV cohort. HIV Med. 2020;21(9):557-566. doi:10.1111/hiv.12901
3. Centers for Disease Control and Prevention. Monitoring Selected National HIV Prevention and Care Objectives by Using HIV Surveillance Data United States and 6 Dependent Areas, 2021. Accessed April 8, 2024.
   http://www.cdc.gov/hiv/library/reports/hiv-surveillance.html
4. Fox MP, Rosen S. Retention of Adult Patients on Antiretroviral Therapy in Low- and Middle-Income Countries: Systematic Review and Meta-analysis 2008-2013. J Acquir Immune Defic Syndr 1999. 2015;69(1):98-108. doi:10.1097/QAI.0000000000000553.
5.  UK cascade data cautions UNAIDS 95:95:95 targets: re-engaging people in care
   https://i-base.info/htb/45425
6. Mirzazadeh A et al. Interventions to reengage people living with HIV who are lost to follow-up from HIV treatment programs: A systematic review and meta-analysis. PLOS Med. 2022;19(3):e1003940. doi:10.1371/journal.pmed.1003940.