New HIV diagnoses and risk factors for late HIV diagnosis, Finland, 2008-2023.

Late HIV diagnosis increases morbidity and mortality. In this retrospective cohort study on the national HIV register, we analysed risk factors for late HIV diagnosis among newly registered people living with HIV (PLWH) between 2008 and 2023, using the updated definition. Of 2683 PLWH registered, 1813 (67.6%) were newly diagnosed with CD4+ T-cell count available ≤90 days for 1572 (86.7%). Eighty-seven of the 609 (14.3%) individuals with CD4+ T-cell count <350/μL had recent infections and were reclassified as non-late. Of the newly diagnosed, 50.3% were diagnosed late. Multivariable analysis identified higher age as an independent risk factor for late diagnosis (adjusted OR 1.42 per ten years, 95% CI 1.30-1.56). Of the Finnish-born, females had lower odds than males (aOR 0.59, 95% CI 0.39-0.88). Asian-born (aOR 6.83, 95% CI 3.49-13.35) and African-born females (aOR 3.26, 95% CI 1.58-6.73) had significantly higher odds than Finnish-born females. In urban municipalities, men who have sex with men had lower odds than individuals with heterosexual transmission (aOR 0.55, 95% CI 0.40-0.76). Higher age was the most important factor for increasing the proportion of late diagnoses. We recommend enhanced testing and risk awareness for older adults and migrants from high-prevalence countries.