Study of Spanish youth transitioning to adult care shows positive outcomes, but some face challenges

Barcelona, Spain. Charisse Kenion/Unsplash.

A study of young people living with HIV in Spain found that after transitioning to adult clinics, virological suppression and CD4 count improved in the following three years. The study led by Dr David Aguilera-Alonso of the Hospital General Universitario Gregorio Marañón is one of the largest published descriptive studies about transition from paediatric care. It appears in the 1 February issue of the Journal of Acquired Immune Deficiency Syndromes.

The study suggests that patients at a higher risk of negative outcomes could be earlier identified. A history of childhood virological failure, being transferred before enrolling onto treatment and having a low CD4 count were the main determinants of a detectable viral load, lower CD4 count post-transition, mortality or loss to follow-up.

“Moving from a... youth-friendly outpatient model, to a system that assumes patient’s autonomy might impact treatment adherence and linkage to care,” write the authors.


virological suppression

Halting of the function or replication of a virus. In HIV, optimal viral suppression is measured as the reduction of viral load (HIV RNA) to undetectable levels and is the goal of antiretroviral therapy.


Lowest of a series of measurements. For example, an individual’s CD4 nadir is their lowest ever measured CD4 count.

detectable viral load

When viral load is detectable, this indicates that HIV is replicating in the body. If the person is taking HIV treatment but their viral load is detectable, the treatment is not working properly. There may still be a risk of HIV transmission to sexual partners.

linkage to care

Refers to an individual’s entry into specialist HIV care after being diagnosed with HIV. 


Relating to the period around the time of birth. Perinatal transmission is when HIV is passed on during pregnancy, childbirth or breastfeeding. People with perinatally-acquired HIV have been living with HIV since birth or infancy.

The study highlights the challenges of facilitating a good experience of transition to adult care. Particularly in HIV, stigma and concerns about sexual and reproductive health add complexities to transition. Paediatric HIV clinics are often a familiar, multi-specialist and family-oriented space, in which minimal autonomy is needed for the patient to engage in care. In comparison, the responsibilities of tracking your own appointments, arranging your own travel and the possibility of rotating staff teams mean that it can often take time for young patients to adjust.

Data came from the Spanish National Cohort of HIV Children (CoRISpe), which includes prospective data from multiple centres across Spain. It currently includes data from 80-85% of all the children and adolescents diagnosed with HIV. The Collaborative Perinatally Acquired HIV Spanish Cohort (FARO), which includes 16 collaborating adult outpatient clinics across Spain, provided follow-up information after transfer to adult care. Data were collected between 1997 and 2016.

The study followed 332 young people, over half of whom were women. At transition, the median age was 18 and they were followed for a median of six years after transition. Forty two per cent of the cohort were males, 8% had foreign parents and 87% were Caucasian.

Baseline data collection began around the age of 12. Data was collected at transition, after one year and after three years. At the moment of transition, the median CD4 count was 668, 88% were on treatment and 67% of them were virologically suppressed (below 200). CD4 count at transition increased throughout the study, with CD4 counts above 500 in 35% of patients between 1997 and 2001, compared to 82% between 2012 and 2016. Viral suppression at transition improved over time, from 27% between 1997 and 2001 to 89% of those transferred between 2012 and 2016.

The researchers looked to see if any of the following were associated with outcomes: sex, being born abroad, foreign parents, ethnicity, year of transition, age at transition, year of diagnosis, age at diagnosis, hepatitis B, hepatitis C, change of centre at transition, antiretroviral therapy status, antiretroviral drug class, once-a-day regimen, one pill-per-day regimen, CD4 nadir (the lowest point to which the CD4 count has ever dropped), CD4 count at transition, non-suppressed viral load at transition and virological failure at transition. They analysed these outcomes three years after transition.

Outcomes improved during follow-up of those on treatment, with rates of virological failure declining from 28% at the time of transition to 14% at the three year follow-up. (Virological failure was defined as two consecutive viral loads over 200 copies.)

The factors (after taking into account confounding variables) associated with virological failure three years after transition were female sex, being born abroad and virological failure at the time of transition.

CD4 counts were stable between transition and three years later, except for increases seen in those who transferred with a CD4 count below 350. Factors associated with a lower CD4 count after three years were Romani heritage, lower age at transition, HIV diagnosis at an earlier year, older age at HIV diagnosis, lower CD4 nadir and CD4 count at transition.

"A lot of the factors leading to negative outcomes link back to the complexities around self-managing care."

Out of 332 young people, 11 patients died due to AIDS-related infections.  In total, 24 people were lost to follow-up. Differences in loss to follow-up were linked to older age at HIV diagnosis, hepatitis C and higher CD4 nadir. There were no differences according to being born abroad, virological failure at transition, foreign parents or transition to a different centre.

There are many examples of transition in care across various settings and health conditions. Yet study results show wide-ranging outcomes: what works in Spain might not work in London. The authors state that the “determinants of a successful transition are unclear.”

For example, a youth-friendly clinic at St Mary’s Hospital, London has good outcomes (such as high engagement and the number of young people remaining virally suppressed), but still saw an increase in mortality when compared to the general population. Another UK study identified that amongst youths with perinatal HIV who died following transition, poor adherence was a determinant factor for an unsuccessful transition. However, most studies have not accounted for factors such as socioeconomics, adherence, patient autonomy, knowledge of the healthcare system and peer support programmes available are not taken into account.

In a Dutch cohort there was a significant increase in virological failure after transition. The characteristics linked to this were challenges with managing adherence at transition and low educational attainment. These findings highlight the wide-ranging results of transition.

The emergence of new antiretrovirals has undoubtedly improved health and quality of life for adolescents, with, for example, dolutegravir (Tivicay) now being approved for this age group.  Yet there are still complexities which continue to influence the outcomes for this population. “The vulnerability of this unique population, which increases during adolescence, has been identified as a key point to be addressed to end the HIV epidemic,” write the authors.

A lot of the factors leading to negative outcomes link back to the complexities around self-managing care. For example, poor treatment adherence in childhood will inevitably have an impact on health outcomes such as resistance and CD4 count. Supporting young people to overcome this is pivotal for them to be able to engage with their continued care.

If you are a young person living with HIV or work with someone who is and would like support around this, CHIVA has provided this resource to help you.


Aguilera-Alonso D et al. Clinical, Immunological, and Virological Outcomes Among Youths With Perinatal HIV After Transition to Adult Units in Spain From 1997 to 2016. Journal of Acquired Immune Deficiency Syndromes, 86: 240-247, February 2021.

doi: 10.1097/QAI.0000000000002539