Loss to follow-up in people living with HIV in Spain: Early disengagement, migrant status, and detectable viral load

Introduction Loss to follow up (LTFU) among people living with HIV is a major clinical and public health challenge, as it is associated with increased risk of onward transmission and higher mortality. Understanding the characteristics of people who are lost to follow-up is essential to improve continuity of care and inform targeted retention strategies. Methods We conducted a retrospective observational study in the Infectious Diseases Unit of Hospital Clínico Universitario de San Juan (Alicante, Spain). We included 209 adults diagnosed with HIV since 2016 and recorded sociodemographic, clinical and virological variables. LTFU was defined, according to GeSIDA criteria, as the absence of clinical visits for ≥12 months. We used bivariate analyses, multivariable logistic regression, and Kaplan–Meier curves to explore factors associated with LTFU and estimate time to LTFU. Results Overall, 23.9% of patients ( n = 50) were LTFU. Compared with retained patients, those LTFU were younger (30.5 vs 34.0 years; p = 0.016), more frequently of non-Spanish nationality (29.8% vs 14.1%; p = 0.010) and less likely to have a stable partner (12.3% vs 29.2%; p = 0.008). Detectable viral load at the last visit was the variable most strongly associated with LTFU (52.4% vs 16.5%; p < 0.001). In the multivariable model, non-Spanish nationality (OR 2.84; 95% CI 1.21–6.62; p = 0.016) and detectable viral load (OR 5.90; 95% CI 2.40–12.50; p < 0.001) remained independently associated with a higher odds of LTFU. The probability of remaining in care at 1, 3 and 5 years was 86.0%, 74.5% and 70.2%, respectively. Conclusions The LTFU rate in our cohort is comparable to that reported in similar high-income settings. Younger age, non-Spanish origin and detectable viral load at last visit were associated with a higher likelihood of LTFU, with a substantial proportion of events occurring early after entry into care. These findings identify young people of non-Spanish nationality with detectable viraemia as a priority group for targeted HIV retention interventions.