O-09 Improving HIV surveillance accuracy through national data cleaning and cohort validation: results of the 2025 HIV treatment e-register review in Guyana
Author(s):
T Jagnarine, M Chalmers
Year of Presentation:
2026
Objective: This study aimed to conduct the first national HIV data-cleaning and verification exercise to establish
a validated treatment cohort, to verify and clean historical HIV treatment records; quantify duplicate, deceased,
migrated, and defaulter cases; distinguish long- vs short term defaulters; and assess the impact on UNAIDS cascade indicators.
Methods: A national retrospective review of 12,824 records included deduplication, outcome verification, and cohort classification. Outcome verification was conducted through systematic review of clinical records, facility reports, and defaulter tracing documentation to confirm mortality and migration, after which records were classified as active in care, long-term defaulters (>7 years), or short-term defaulters (30 days–6 years) using standardised national definitions.
Results: A total of 401 duplicates (3.1%) were identified; 1,308 deaths (10.2%), and 454 migrations (3.5%), producing a validated eligible cohort of 10,661 PLHIV, thereby correcting 13.7% denominator inflation. Of eligible clients, 7,268 (68.2%) were active, 2,071 (19.4%) long-term defaulters, and 1,322 (12.4%) short-term defaulters. Distribution differed significantly from expectation (χ² < 0.001). Re-engagement modelling showed improvements of +2.7 percentage points at 25% return, and +6.4 percentage points at 60%, indicating strong potential for accelerating the third UNAIDS 95 Target.
Conclusion: National data validation substantially improved surveillance precision and clarified programmatic gaps. Re-engagement of short-term defaulters represents a high-impact route to increasing viral suppression. Guyana’s 2025 exercise provides a replicable model for regional HIV monitoring improvement and progress toward epidemic control.