Abstract
Loss to follow-up (LTFU) among people living with HIV (PLHIV) is a concerning reality in various healthcare services and can occur at any stage of HIV care. LTFU can lead to a decline in overall health and quality of life for PLHIV; moreover, antiretroviral therapy (ART) interruption increase the risk of HIV sexual transmission. This systematic review investigated factors related to LTFU among PLHIV. The review included sources from PubMed, Cochrane Library, Embase, and others. We included observational studies published in English, Spanish, or Portuguese, from January 1, 2004, to December 31, 2024. We identified 36 studies from 20 countries in North and South America, Europe, Asia, and Africa. The studies included 69,789 PLHIV, of whom 22% were classified as LTFU. The time frame used to define LTFU varied across studies, ranging from 14 to 365 days. The most frequently reported factors associated with LTFU were younger age, low educational level, financial instability, illicit drug use, stigma, absence of family and social support, and ART side effects. Other relevant factors included long commuting time to healthcare facilities, long waiting time at health units, and issues with provider-patient relationships. Multiple factors may contribute to LTFU among PLHIV in complex and context-dependent ways. To address this issue, healthcare services must develop a comprehensive understanding of the communities they assist, recognizing distinct subgroups and their specific needs. Public health policies should be implemented to promote continuous care for PLHIV, including early diagnosis, multidisciplinary assessment, and social support.