{
  "abstract": "Background This study aimed to describe pre-exposure prophylaxis (PrEP) for HIV use in the Lombardy Region, quantifying users, outlining their demographic characteristics, and exploring patterns of use.Material and Methods Administrative data on antiretroviral (ARV) drugs prescribed through NHS were used to identify PrEP users, defined as individuals receiving TDF/FTC. To avoid including people with HIV (PWH) or post-exposure prophylaxis, users were censored at the first prescription of another ARV. Data from 1 June 2023 to 31 December 2025 were included for patients aged ≥18 years. Age, sex, and place of birth were recorded at PrEP initiation. Daily vs on-demand use was explored by calculating the medical refill ratio (MRxR), defined as the total number of tablets dispensed divided by the number of days between the first and last visit. Linear regression was used to assess the association between age and MRxR. Number of infections in PrEP users is systematically recorded from July 2025.Results A total of 6,938 PrEP users were identified; 98% were male, 84% were born in Italy, and the median age was 36 years (IQR 30–44). Overall, 3,951 (57%) resided in the Milan metropolitan area. PrEP initiation was recorded for 2,502 users in 2023, 2,348 in 2024, and 2,088 in 2025.Figure 1 presents the cumulative distribution of individuals according to MRxR. Among the 5,396 users with at least two prescriptions, 24.5% had an MRxR ≥0.85, corresponding to approximately six tablets per week. No meaningful association was observed between age and MRxR (R2 = 0.09%). Among the 6,938 users who started PrEP, 5,601 (80%) were dispensed at least one tablet in 2025. Six new HIV infections were reported among individuals using PrEP from July 2025 onward. Of these, one reported ≥6 tablets/week, two daily use with unknown or low adherence, and three on-demand use.Conclusions Since reimbursement was introduced, PrEP uptake in the Lombardy Region has increased; however, individuals recorded as new users in 2023 were likely already receiving PrEP out-of-pocket. Refill patterns show marked heterogeneity, and unfortunately, administrative data cannot distinguish between appropriate on-demand use and suboptimal adherence.Using as a proxy denominator the 5,601 individuals who received at least one tablet in 2025, six new HIV infections were recorded from July 2025 onward (0.1%). Only one occurred in a person who self-reported consistent daily use. Although few infections were observed, potential gaps in protection may persist, and continued monitoring is warranted to better understand this phenomenon.Current PrEP scale is unlikely to be sufficient to substantially impact HIV incidence. The Lombardy Region has a strategic responsibility in consolidating integrated surveillance, expanding equitable access to PrEP, and strengthening adherence support to maximize the population-level impact of HIV prevention.Abstract P179 Figure 1Cumulative percentage for total MRxR (number of users = 5396)",
  "authors": [
    {
      "affiliations": [
        "ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "D Moschese"
    },
    {
      "affiliations": [
        "Vita-Salute San Raffaele University, Milan, Italy"
      ],
      "name": "S Nozza"
    },
    {
      "affiliations": [
        "ASST GOM Niguarda, Milan Italy"
      ],
      "name": "N B Bana"
    },
    {
      "affiliations": [
        "ASST Santi Paolo e Carlo, Milan, Italy"
      ],
      "name": "G Ancona"
    },
    {
      "affiliations": [
        "ASST Ovest Milanese, Legnano, Italy"
      ],
      "name": "D Bernacchia"
    },
    {
      "affiliations": [
        "ASST Lecco, Lecco, Italy"
      ],
      "name": "A Pandolfo"
    },
    {
      "affiliations": [
        "ASST Papa Giovanni XXIII, Bergamo, Italy"
      ],
      "name": "S Venturelli"
    },
    {
      "affiliations": [
        "ASST Spedali Civili di Brescia, Brescia, Italy"
      ],
      "name": "E Focà"
    },
    {
      "affiliations": [
        "ASST Cremona"
      ],
      "name": "C Fornabaio"
    },
    {
      "affiliations": [
        "ASST Valle Olona, Busto Arsizio, Italy"
      ],
      "name": "D Radrizzani"
    },
    {
      "affiliations": [
        "Fondazione IRCCS Policlinico San Matteo, Pavia, Italy"
      ],
      "name": "L Pagnucco"
    },
    {
      "affiliations": [
        "Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy"
      ],
      "name": "A Muscatello"
    },
    {
      "affiliations": [
        "Fondazione IRCCS San Gerardo dei Tintori, Monza, Italy"
      ],
      "name": "L Corsico"
    },
    {
      "affiliations": [
        "Directorate General for Health – Lombardy Region, Milan, Italy"
      ],
      "name": "G Del Castillo"
    },
    {
      "affiliations": [
        "ASST Fatebenefratelli Sacco, Milan, Italy"
      ],
      "name": "M Maffeo"
    },
    {
      "affiliations": [
        "Directorate General for Health – Lombardy Region, Milan, Italy"
      ],
      "name": "D Cereda"
    }
  ],
  "title": "P179 PrEP implementation in the Lombardy region: coverage, adherence heterogeneity, and implications for HIV prevention",
  "uid": "e2000c6f-0b3b-5ded-abac-2478595221c5"
}