Angelos Hatzakis’s research while affiliated with National and Kapodistrian University of Athens and other places

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Publications (331)


Building digital trust among people who use drugs (PWUD). We identified extensive use of the internet for healthcare purposes within a PWUD population with internet access (Theme 1). Despite limited experience with telehealth among FGD participants, they frequently used the internet for accessing healthcare information, scheduling appointments with healthcare providers, and obtaining medication prescriptions. Most participants perceived telehealth benefits, such as convenience, its time-saving nature, and the ease of establishing trust with healthcare providers (Theme 2). Participants agreed that these benefits outweigh telehealth’s perceived limitations, such as the inability to conduct physical examinations. However, some participants recognized that the inability to conduct physical examinations through telehealth results in reduced diagnostic accuracy compared to in-person assessments. These concerns led some participants to categorically oppose using telehealth. Participants also perceived major barriers to telehealth engagement, such as prioritization of addiction issues over healthcare, limited accessibility to technological infrastructure, and low digital literacy. Despite the reported perceived challenges, PWUD expressed a strong willingness to embrace telehealth as a healthcare delivery method and provided several suggestions to enable its widespread adoption within their communities. Participants’ suggestions included recommending an initial in-person visit before transitioning to telehealth, emphasizing the maintenance of eye contact during telehealth sessions to promote digital trust, and requesting education on how to effectively utilize telehealth services (Theme 3). Participants also believed that addressing technology accessibility limitations could be achieved through partnerships with community organizations that provide telehealth-related infrastructure, supported by physicians and the government. The identified themes support telehealth’s potential as an innovative solution to expand healthcare access for PWUD
Telehealth to increase healthcare access; perspectives of people who use drugs
  • Article
  • Full-text available

October 2024

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21 Reads

BMC Medical Informatics and Decision Making

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Elisavet Ntagianta

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Vasiliki Triantafyllou

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[...]

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Andrew H. Talal

Background People who use drugs (PWUD) often face restricted healthcare access despite their heightened healthcare needs. Factors such as stigma, mistrust of the healthcare system, competing priorities, and geographical barriers pose significant healthcare access challenges. Telehealth offers an innovative solution to expand healthcare access for better inclusion of underserved populations in healthcare. We aimed to explore PWUDs’ perceptions of telehealth as a healthcare delivery modality. Methods We utilized purposive sampling to recruit participants (N = 57) for nine focus group discussions (FGDs) in Athens, Greece. Eligibility criteria required participants to be at least 18 years, with current or prior injection drug use, and current internet access. The FGDs followed a semi-structured interview guide, were audio recorded, transcribed verbatim, translated into English, and de-identified. We applied thematic analysis to analyze FGD transcripts. Results Participants’ mean (standard deviation) age was 47.9 (8.9) years, 89.5% (51/57) were male, 91.2% (52/57) were of Greek origin, and 61.4% (35/57) had attended at least 10 years of school. Three main themes emerged from the FGDs: (1) high internet utilization for healthcare-related purposes among PWUD, (2) highlighting telehealth benefits despite access obstacles and PWUDs’ concerns about diagnostic accuracy, and (3) approaches to overcome access obstacles and build digital trust. Participants extensively used the internet for healthcare-related processes, such as accessing healthcare information and scheduling provider appointments. Despite being telehealth-inexperienced, most participants expressed a strong willingness to embrace telehealth due to its perceived convenience, time-saving nature, and trusted digital environment. Some participants recognized that the inability to conduct physical examinations through telehealth reduces its diagnostic accuracy, while others expressed concerns about digital literacy and technological infrastructure accessibility. Most participants expressed a preference for video-based telehealth encounters over audio-only encounters. To build trust in telehealth and promote patient-centeredness, participants recommended an initial in-person visit, virtual eye contact during telehealth encounters, patient education, and partnerships with PWUD-supportive community organizations equipped with appropriate infrastructure. Conclusions PWUD frequently use the internet for health-related purposes and suggested several approaches to enhance virtual trust. Their insights and suggestions are practical guidance for policymakers seeking to enhance healthcare access for underserved populations through telehealth. Trial registration NCT05794984.

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Considerations for Equitable Distribution of Digital Healthcare for People Who Use Drugs

August 2024

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26 Reads

Background: Telehealth holds the potential to expand healthcare access for people who use drugs (PWUD). However, approaches to increase PWUDs’ access to digital healthcare are not well-understood. We studied digital healthcare accessibility among PWUD. Methods: We employed respondent-driven sampling to recruit 162 PWUD in Athens, Greece to collect data via a structured questionnaire. Participants were aged at least 18 years and had an injection drug use (IDU) history. We assessed current internet and computer access, and experience with telemedicine. We utilized logistic regression to evaluate sociodemographic associations. Results: Participants' mean (standard deviation) age was 45.9 (8.8) years, 84.0% were male, 90.1% Greek, 77.8% reported IDU within the past year, 85.2% were not linked to opioid treatment, and 50.0% were currently experiencing homelessness. Only 1.9% had experience and 46.3% had familiarity with telemedicine. Internet and computer access were reported by 66.0% and 31.5% of participants, respectively. Compared to participants with secure housing, those currently experiencing homelessness reported decreased internet (50.6% vs 81.5%, p<0.001) and computer access (11.1% vs 51.9%, p<0.001). Multivariable analyses revealed that older age (per 1-year increase: odds ratio [OR]=0.94, 95% confidence interval [CI] [0.89, 0.99], p=0.03), IDU within the past year (0.29 [0.10, 0.88], p=0.03), and homelessness (0.29, [0.13, 0.65], p=0.003) were associated with lower odds of internet access. Homelessness was associated with lower odds of computer access (0.17, [0.07, 0.41], p<0.001). Conclusions: Internet and infrastructure challenges, homelessness, and digital literacy gaps should be considered to bridge the digital divide and ensure equitable digital healthcare distribution for PWUD. Clintrials.gov registration number: NCT05794984


Telehealth to increase healthcare access; perspectives of people who use drugs

June 2024

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31 Reads

Background: People who use drugs (PWUD) often face restricted healthcare access despite their heightened healthcare needs. Factors such as stigma, mistrust of the healthcare system, competing priorities, and geographical barriers pose significant challenges to accessing healthcare services for PWUD. Telehealth offers an innovative solution to expand healthcare access for better inclusion of underserved populations in healthcare. We aimed to explore PWUDs’ perceptions of telehealth as a healthcare delivery modality. Methods: We utilized purposive sampling to recruit participants (N = 57) for nine focus group discussions (FGDs) in Athens, Greece. Eligibility criteria required participants to be at least 18 years old, with a history of injection drug use, and current internet access. The FGDs followed a semi-structured interview guide, were audio recorded, transcribed verbatim, translated into English, and de-identified. We applied thematic analysis to analyze FGD transcripts. Results: Participants’ mean (standard deviation) age was 47.9 (8.9) years, 89.5% (51/57) were male, 91.2% (52/57) were of Greek origin, and 61.4% (35/57) had attended at least 10 years of school. Three main themes emerged from the FGDs: (1) high internet utilization for healthcare-related purposes among PWUD, (2) highlighting telehealth benefits despite access obstacles and PWUDs’ concerns about diagnostic accuracy, and (3) approaches to overcome access obstacles and build digital trust. Participants extensively used the internet for healthcare-related processes such as accessing healthcare information and scheduling provider appointments. Despite being telehealth-inexperienced, most participants expressed a strong willingness to embrace telehealth due to its perceived convenience, time-saving nature, and trusted digital environment. Some participants perceived the inability to conduct a physical examination during telehealth encounters as limiting its diagnostic accuracy, while others expressed concerns about digital literacy and technological infrastructure accessibility. To build trust in telehealth and promote patient-centeredness, participants recommended an initial in-person visit, virtual eye contact during telehealth encounters, patient education, and partnerships with PWUD-supportive community organizations equipped with appropriate infrastructure. Conclusions: PWUD frequently use the internet for health-related purposes and suggested several approaches to enhance virtual trust. Their insights and suggestions are practical guidance for policymakers seeking to enhance healthcare access for underserved populations through telehealth. Clintrials.gov registration number: NCT05794984




Incidence of primary hepatitis C infection among people who inject drugs during 2012–2020 in Athens, Greece

May 2024

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43 Reads

Journal of Viral Hepatitis

One of the World Health Organization's targets for the 2030 viral hepatitis elimination strategy is to reduce new hepatitis C (HCV) infections. In Athens, Greece, people who inject drugs (PWID) have a high HCV prevalence, with increasing trends since the 2000s. This analysis aims to assess primary HCV incidence among PWID during 2012–2020. Two community‐based interventions were implemented in 2012–2013 and 2018–2020 with repeated sero‐behavioural surveys in each period. Participants enrolled in multiple surveys were identified through linkage. To assess trends in HCV transmission, three indicators were estimated: (i) anti‐HCV prevalence among ‘new’ injectors (those injecting ≤2 years), (ii) indirect HCV incidence among ‘new’ injectors, assuming infection occurred at the midpoint between initiating injection and the first positive test, and (iii) HCV incidence from repeat participants. There were 431 and 125 ‘new’ injectors, respectively, in 2012–2013 and 2018–2020. Αnti‐HCV prevalence [95% CI] declined from 53.6% [48.8%, 58.3%] in 2012–2013 to 40.0% [31.3, 49.1%] in 2018–2020 (25.4% reduction, p = .007). The indirect estimate [95% CI] of HCV incidence among ‘new’ injectors decreased from 56.1 [49.3, 63.8] to 39.0/100 person‐years (PYs) [29.6, 51.5] (30.5% reduction, p = .020). HCV incidence [95% CI] based on seroconversions in repeat participants (16/63 in 2012–2013 and 9/55 in 2018–2020) declined from 64.6 [39.6105.4] to 13.8/100 PYs [7.2, 26.5], respectively (78.6% reduction, p < .001). Primary HCV incidence remains high among PWID in Athens. Consistent implementation of combined interventions, including high‐coverage harm reduction programs and initiatives tailored to increase access to HCV treatment, is essential to sustain the declining trends documented during 2012–2020.






Citations (59)


... To our knowledge, this is the first study to report on the specific cause of death within recent HIV outbreak cohorts of PWID. The only other recent study to date examining mortality among PWID in the context of an HIV outbreak estimated ACM among PWID in Athens, Greece [27]. They reported that HIV infection was associated with an increase in ACM and that PWID living with HIV had more than double (32.12) the standardized mortality ratio (SMR) than PWID who were HIV-negative (14.00). ...

Reference:

Rising mortality among people who inject drugs living with HIV in Scotland, UK: A 20‐year retrospective cohort study
High levels of all-cause mortality among people who inject drugs from 2018 to 2022
  • Citing Article
  • February 2024

International Journal of Drug Policy

... Recent studies have estimated a global prevalence of HBV infection between 3.2% to 3.8% [54,55]. Razavi-Schearer and colleagues (2023) further estimated a 1.1% prevalence of HBV infection in Portugal [54], which is a closer value to that observed in the present study (0.6%). ...

Global prevalence, cascade of care, and prophylaxis coverage of hepatitis B in 2022: a modelling study

The Lancet Gastroenterology & Hepatology

... However, it should be noted that multiple vaccinations do not always result in an increase in antibody levels in SOTRs [17,18]. Overall, seroconversion rates after COVID-19 vaccination in this group of patients vary from reports and mainly depend on individual characteristics, the type of transplanted organ, the medications taken, the kind of vaccine used, and the number of administered doses [5,7,17,19,20]. Four months after the rise in antibody levels following the additional dose, the woman's antibody levels began to decline, and at the sixth checkpoint they were twice as low as they were at the previous one. This may have contributed to the breakthrough infection identified in her during this time, but importantly, she passed it very gently. ...

Assessment of mRNA Vaccine Immunogenicity in Solid Organ Transplant Recipients

Medicina

... Since the reporting of MOs in a single-centre study in 2016 [20], the Greek HIV epidemic has undergone notable changes, notably with an increased frequency of new cases among non-Greek ethnicities and heterosexual individuals [7]. The incidence of HIV among PWID has remained stable since the original HIV outbreak in this population approximately a decade ago in Athens, while another one has emerged in an urban area beyond Athens during the COVID-19 pandemic [21,22]. ...

A new outbreak of HIV infection among people who inject drugs during the COVID-19 pandemic in Greece
  • Citing Article
  • May 2023

International Journal of Drug Policy

... The reasons why patients on kidney replacement therapy have a weaker innate and adaptive immune system responsible for the immune response are multifaceted. They include-uremia-induced suppression of the immune system, which leads to a reduced cellmediated and antibody-mediated immune response and a faster decrease in antibody titers due to impaired functions of T and B lymphocytes [11]. In addition, other risk factors have been identified, such as older age, diabetes, obesity, cancer, cirrhosis, cardiovascular disease, malnutrition and inflammation, oxidative stress, which impair the protective immunity of hemodialysis patients [12]. ...

Immunogenicity of the Two mRNA SARS-CoV-2 Vaccines in a Large Cohort of Dialysis Patients

Infectious Disease Reports

... Furthermore, patients diagnosed with various malignancies (Benitez Fuentes et al., 2022;Diamantopoulos et al., 2022;Goldwater et al., 2023;Ollila et al., 2022;Storti et al., 2022;Tanzilli et al., 2022;Terpos et al., 2022) or immune deficiencies (Fidler et al., 2023;Gianserra et al., 2022;Kling et al., 2023) experience a more severe course of illness due to a combination of their immunosuppressive medications and the nature of their underlying condition. The use of immunosuppressive medications is significantly associated with the severity of COVID-19 and increased hospitalizations (Kontopoulou et al., 2022;Shapiro Ben David et al., 2022). ...

Immunogenicity of a third dose of the BNT162b2 COVID-19 vaccine in patients with CLL: effects on treatment selection

Annals of Hematology

... The selection of a 5-year data collection span was based on the available data from the only Greek dataset on determinants for HIV late presentation with molecular clock-inferred HIV infection dates [14], alongside other international publications [15]. To assess HCCs within 5 years preceding the case's HIV infection diagnosis, the data were reviewed by two independent, anonymised reviewers. ...

Estimation of the determinants for HIV late presentation using the traditional definition and molecular clock‐inferred dates: Evidence that older age, heterosexual risk group and more recent diagnosis are prognostic factors

... While it identified over a third of infected but mildly or asymptomatic individuals, the antigen tests' sensitivity was notably lower than in the initial validation studies, missing nearly a third of infectious cases. 159,160,167,168 ...

Securing Wider EU Commitment to the Elimination of HCV
  • Citing Article
  • October 2022

Liver international: official journal of the International Association for the Study of the Liver

... The emergence of SARS-CoV-2 infection in 2019 and the unprecedented focus generated towards the disease , has once again highlighted the general neglect of the global community towards diseases of public health importance that disproportionately afflict nations in the lower and the middle-income bracket of the global economic spectrum (1,2) . Of these "neglected" infectious diseases of public health importance, the annual mortality for malaria, tuberculosis and HIV have been decreasing over the years whereas mortality attributable to viral hepatitis infection has been increasing (3) . ...

The Case for Simplifying and Using Absolute Targets for Viral Hepatitis Elimination Goals
  • Citing Article
  • January 2021

... The absence of systematic adverse events seems to agree with a study in which no significant adverse effects were observed in patients with CLL who were treated with BTKi, but they were not treated with a full-dose of the anti-coagulant, which may be necessary in patients with severe forms of COVID-19 [50,51]. Other common variables for poor vaccine response have been identified, mainly hypogammaglobulinemia and age > 65-70 years, in addition to being on active medication [52,53]. ...

Safety and immunogenicity of the BNT162b2 mRNA Covid-19 vaccine in patients with chronic lymphocytic leukemia: a prospective study