Abstract
WHAT IS ALREADY KNOWN ABOUT THIS TOPIC? Late human immunodeficiency virus (HIV) diagnosis remains prevalent among older adults in China; however, recent national-level evidence characterizing its correlates remains limited. WHAT IS ADDED BY THIS REPORT? Using nationwide surveillance data spanning 2022-2024 and employing two complementary analytical approaches, this study identified transmission route and geographic region as primary correlates of late HIV diagnosis. Decision-tree analysis further identified two distinct subgroups in eastern China exhibiting particularly elevated proportions of late diagnosis. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE? These findings provide epidemiological evidence to inform more targeted HIV screening strategies tailored to specific population subgroups, geographic regions, and diagnostic settings.