Defining linkage to care following human immunodeficiency virus (HIV) diagnosis for public health monitoring in Europe.

Prompt linkage to human immunodeficiency virus (HIV) care after diagnosis is crucial to ensure optimal patient outcomes. However, few countries monitor this important public health marker and different definitions have been applied, making country and study comparisons difficult. This article presents an expert-agreed, standard definition of linkage to care for a pragmatic approach to public health monitoring, appropriate to the European context. Here, linkage to care is defined as patient entry into specialist HIV care after diagnosis, measured as the time between the HIV diagnosis date and one of the following markers: either the first clinic attendance date, first CD4+ cell count or viral load date, or HIV treatment start date, depending on data availability; Linkage is considered prompt if within 3 months of diagnosis. Application of this definition by researchers and public health professionals when reporting surveillance or research data relating to linkage to care after HIV diagnosis will enable reliable comparisons across countries, better assessment of the success of health services programmes aimed at improving peoples access to HIV treatment and care and the identification of barriers limiting access to HIV care across Europe.