Revisiting Anti-HCV Seropositivity: Signal Intensity, Diagnostic Uncertainty, and the Limitations of Fixed Cut-Offs
Diagnostics·
- DOI
- 10.3390/diagnostics16162665
- PMID
- —
- PMCID
- —
- OpenAlex
- —
- Study type
- Journal article
- Publisher
- MDPI AG
- Article type
- journal-article
- Integrity
- current
Why this research matters now
Findings suggest graded, signal-based interpretation of anti-HCV reactivity may reduce unnecessary confirmatory testing and clarify low-level reactivity in screening contexts.
Structured evidence summary
Research question
The study examines whether anti-HCV signal-to-cutoff values can be used to stratify diagnostic uncertainty and reduce unnecessary confirmatory testing in reactive antibody results.
Study design
Retrospective diagnostic accuracy study using ROC analysis and multivariable logistic regression on a large screened cohort, with infection status assigned by a uniform HCV-RNA PCR reference standard.
Population and setting
The analysis covered 565,726 anti-HCV test results, restricted to a reactive subset of 2,950 individuals (≥1.0 S/Co), including 1,581 with true HCV infection and 1,369 without.
Main findings
Anti-HCV signal intensity showed strong discrimination across the reactive cohort (AUC 0.991) but weaker performance in the 1.00–4.99 S/Co uncertainty interval (AUC 0.832), where only 5.7% of reactive results reflected true infection. A Youden-optimal threshold of 4.65 S/Co yielded sensitivity, specificity, and positive predictive value above 95%, and each doubling of S/Co raised infection odds roughly 23-fold. Within the uncertainty interval, no threshold achieved a positive predictive value above 58.2%, and restricting confirmatory testing to results above 2.50 S/Co could avoid 41.7% of confirmations at the cost of missing 1.96% of true infections.
Public-health relevance
Findings suggest graded, signal-based interpretation of anti-HCV reactivity may reduce unnecessary confirmatory testing and clarify low-level reactivity in screening contexts.
Important limitations
Summary is limited to the supplied single-article abstract and metadata; the original paper is required for decision-grade interpretation. The abstract does not explicitly state additional limitations such as generalizability, population scope, or assay platform effects.
GIDS interpretation
This single peer-reviewed diagnostic-accuracy study provides context on interpretation of anti-HCV screening signals but is not itself a surveillance signal and does not establish population-level prevalence or trends.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 5 auditable classifier relationships to diseases, places, topics, and study design.