In Italy, 60% of new HIV diagnoses are in people who already have advanced disease (i.e., a CD4 count <350 cells/mm3) (1). This highlights an urgent need for alternative screening strategies if Italy is to make progress towards achieving the UNAIDS target of diagnosing at least 95% of people living with HIV (2).
Recent studies from England, Ireland, and Portugal have demonstrated the real-world clinical effectiveness of universal opt-out ED testing strategies in regions with medium to high HIV prevalence showing an increased number of HIV diagnoses and patients linked to care (3–7). We developed a theoretical model to evaluate whether such a screening strategy would be cost-effective in Italy. The results of the model, presented in June at the 16th Italian Conference on AIDS and Antiviral Research (ICAR), indicate that universal opt-out screening would increase the number of new HIV diagnoses and likely be cost-effective.
We developed a closed-cohort hybrid decision tree Markov model in Excel. The model compared universal opt-out screening with standard of care (SoC), which in Italy is indicator testing of patients presenting with opportunistic infections. This approach results in missed opportunities for HIV diagnosis, leading to higher morbidity and mortality in late-diagnosed individuals as well as continued HIV transmission (4).
Data from Italy were used to inform the model inputs. Where no data from Italy were available, data from an evaluation of HIV screening in Portugal were used (in the primary analysis) including HIV prevalence, something likely to vary by region and a crucial input for determining the cost-effectiveness of any screening strategy.
We found that universal opt-out screening of ED attendees is cost-effective when the HIV prevalence is 0.25% or above, assuming a willingness-to-pay threshold of €30,000 per QALY (8). This prevalence threshold is similar to the 0.2% threshold above which NICE recommends ED HIV testing in the UK (>0.2%) (9). This threshold may be particularly useful to inform decision-makers at regional and local levels in Italy where healthcare investments happen at a regional level.
The full results of the model, including the results of secondary analysis and a number of scenario analyses, will be published as a peer-reviewed article in the autumn.
This study was commissioned and funded by Gilead Sciences.
Citation
1. L’Istituto Superiore di Sanità. Notizario dell’Instituto Superiore di Sanita – AGGIORNAMENTO DELLE NUOVE DIAGNOSI DI INFEZIONE DA HIV E DEI CASI DI AIDS IN ITALIA [Internet]. 2023 Nov. Report No.: Volume 36-Number 11. Available from: https://www.salute.gov.it/imgs/C_17_pubblicazioni_3377_allegato.pdf
2. 2025 Aids Targets [Internet]. UNAIDS; [cited 2024 Apr 9]. Available from: https://www.unaids.org/sites/default/files/2025-AIDS-Targets_en.pdf
3. Parry S, Bundle N, Ullah S, Foster GR, Ahmad K, Tong CYW, et al. Implementing routine blood-borne virus testing for HCV, HBV and HIV at a London Emergency Department – uncovering the iceberg? Epidemiol Infect. 2018 Jun;146(8):1026–35.
4. Smout E, Phyu K, Hughes GJ, Parker L, Rezai R, Evans A, et al. Real-world clinical effectiveness and sustainability of universal bloodborne virus testing in an urban emergency department in the UK. Sci Rep. 2022 Nov 10;12(1):19257.
5. Vaz‐Pinto I, Gorgulho A, Esteves C, Guimarães M, Castro V, Carrodeguas A, et al. Increasing HIV early diagnosis by implementing an automated screening strategy in emergency departments. HIV Med. 2022 Dec;23(11):1153–62.
6. Hill-Trout R. Implementation of routine opt out Blood Borne Virus (BBV) screening in 34 Emergency Departments (EDs) in areas of extremely high HIV prevalence in England. In Gateshead, UK: NHSE BHIVA;
7. O’Connell S, Lillis D, Cotter A, O’Dea S, Tuite H, Fleming C, et al. Opt-Out Panel Testing for HIV, Hepatitis B and Hepatitis C in an Urban Emergency Department: A Pilot Study. Khudyakov YE, editor. PLOS ONE. 2016 Mar 11;11(3):e0150546.
8. Monforte A d’Arminio, d’Ettorre G, Galardo G, Doornewaard A van, Lani E, Kagenaar E, et al. OC-4 Estimating the potential health economic value of universal opt-out HIV testing in emergency departments in Italy: a modelling study. Sex Transm Infect. 2024 Jun 1;100(Suppl 1):A4–5.
9. Recommendations | HIV testing: increasing uptake among people who may have undiagnosed HIV | Guidance | NICE [Internet]. NICE; 2016 [cited 2024 Sep 4]. Available from: https://www.nice.org.uk/guidance/ng60/chapter/recommendations#offering-and-recommending-hiv-testing-in-different-settings
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