In this study, we aimed to characterise PC disease presentation features nationally in Ireland, specifically focusing on identifying factors associated with socio demographic disparities in presentation subsequent to opportunistic screening. While our analysis did reveal some statistically significant associations, it is important to note that these associations may not necessarily translate into clinical significance. Nevertheless, our study adds considerable value to existing research by providing timely and comprehensive nationwide information, encompassing both public and private sectors. This wide-ranging approach ensures a more representative and holistic understanding across different healthcare settings.

Our findings indicate that patients in urban areas are diagnosed with more advanced PC, marked by higher PSA levels, increased metastatic rates, and higher ISUP grades compared to those in rural areas. Despite slightly higher rates of presentation following opportunistic screening in urban areas, these findings suggest that urban patients may be diagnosed at later stages. This may stem from multiple factors. One explanation could be related to urban healthcare systems being burdened by longer wait times, particularly in the public sector, leading to delays in both diagnosis and treatment. Studies from countries such as Australia and the U.S. have similarly identified urban populations facing access issues due to healthcare system overloads despite their proximity to services [23]. Although urban residents may engage in opportunistic screening, they still face access issues. Further exploration into these factors is necessary to fully understand the mechanisms driving urban-rural disparities. Future research should focus on how environmental stressors, healthcare access, and rural-urban screening differences influence PC diagnosis.

Additionally, we observed a non-linear pattern in disease presentation across different SES groups, with middle SES groups showing lower rates of opportunistic screening, implying poorer access to screening. This might be caused by financial and structural barriers limiting their access to healthcare services. Ireland’s two-tiered public-private healthcare system may explain this anomaly. While men in the 2nd and 3rd SES quintiles may not afford private insurance, they also may not be eligible for social medical coverage [24]. These men may avoid opportunistic screening since GP visits are costly. Our multivariable analysis, which accounted for dependencies between different socioeconomic and demographic variables, found that presentation following screening is more likely in public and urban settings. Public hospitals equipped with structured pathways, such as the RAPCs, facilitate efficient referral and diagnostic processes. Urban settings typically offer better access to healthcare facilities and resources. Conversely, age is negatively associated with presentation following screening, suggesting that older men are less likely to undergo screening. This may be due to comorbidities, reduced healthcare-seeking behaviour, or potential biases caused by screening recommendations for older populations.

Previous studies have extensively investigated the relationship between socio demographic or socio economic factors and PC presentation and outcomes, providing a valuable foundation for contextualising our findings. Weiner et al. utilised SEER data to investigate disparities in PC presentation [25]. Their research highlighted the independent associations between lower SES, race/ethnicity, the absence of private insurance coverage, and a higher likelihood of presenting with metastatic de-novo disease. Our study similarly identifies SES as a significant factor in PC presentation, particularly noting a U-shaped trend across different SES quintiles. In a separate study, Foley et al. examined PC cases in Tasmania [26], revealing that men from remote areas who lived in lower socio economic regions are diagnosed at an older age and present with more clinically aggressive PC features. Contrarily, our study found that patients in urban areas were diagnosed with more advanced PC than those in rural areas. While our study also identified SES as a key factor in more advanced PC presentation, the relationship we revealed is more complex. We can attribute the different findings to the unique Irish social and healthcare features.

In the Irish context, a 2023 report by the National Cancer Registry examining cancer disparities in Ireland, spanning the years 2004 to 2018, provided a detailed exploration of inequalities, also focusing on PC [27]. This report follows a 2016 report which covered the years 2008-2012 [28]. These reports revealed significant differences in the stage at diagnosis influenced by rural-urban status and socio economic deprivation. It was observed that urban patients were diagnosed at a more advanced stage in comparison to rural patients. Moreover, patients from the most socio-economically deprived backgrounds were less likely to be diagnosed at an earlier stage relative to those from the least deprived groups. Our study aligns with these findings, adding nuance to the relationship between SES and PC presentation. The Think-tank for Action on Social Change (TASC) report from 2022 focused on investigating the impact of socio-economic inequalities on access to cancer services in Ireland [29]. Although concentrating on specific cancers that show higher morbidity rates in disadvantaged and marginalised population groups, this report also sheds some light on PC disparities in Ireland. The report highlights that an individual’s economic and social resources influence their cancer journey and outcomes. Social inequalities lead to various barriers, ranging from delayed access to primary care and financial burdens of treatment to psychological obstacles like stigma and the fear of financial hardship. Our study’s observations on the socio economic disparities in opportunistic screening resonate with the TASC report’s emphasis on barriers related to care access.

Our findings highlight the need for targeted interventions to improve access and encourage screening and have significant implications for the organisation of PC screening in Ireland. Implementing risk-based, tailored screening programs that consider SES and geographical location could enhance early detection and reduce advanced disease presentations. Public awareness campaigns should be increased to emphasise the importance of PC screening, especially targeting those in rural or deprived areas. Additionally, implementing policies aimed at reducing the financial burden of screening for men from middle or lower-SES backgrounds and enhancing accecability is crucial. These measures collectively aim to reduce disparities and improve overall health outcomes.

While our study has provided valuable insights into the factors influencing PC presentation, it is essential to acknowledge and address the limitations that may have impacted the interpretation and generalisability of our findings. One significant limitation of this study stems from its observational nature. As an observational study, we relied on the analysis of pre-existing data and the selection of patients from sites that participated in the study, not covering all men diagnosed with PC in Ireland. This lack of control can introduce confounding variables and biases that may affect the internal validity of our results. Therefore, caution should be exercised when interpreting causal relationships based on our observational findings. Another limitation of this study is the irregular distribution of missing data across various study sites, which could be attributed to the varying data collection practices and clinical practices at each site. A sensitivity analysis was performed to mitigate this limitation, incorporating only sites with a low percentage of missing data. As noted earlier, the outcomes of this analysis were consistent with the complete case analysis, thereby supporting the validity of generalising the results at a national level.

Another notable limitation of our study is the lack of consideration of race or ethnicity as a potential factor influencing disparities in PC presentation. While a substantial body of literature examines racial inequality in PC outcomes, it is essential to acknowledge that our study did not collect race information. Thus, the investigation of racial disparities falls outside the scope of our research. While we recognise the significance of this factor, our study primarily focused on other socio demographic and socio economic aspects. It aimed to shed light on potential challenges within Ireland’s healthcare system. Future studies specifically designed to examine racial disparities in PC are warranted to provide a more comprehensive understanding of this complex issue. Finally, it is crucial to note that our study focused primarily on disparities in the initial stage of PC presentation. It did not investigate potential disparities in subsequent stages of the patient journey, such as access to disease staging investigation, treatments or outcomes. This warrants further exploration in future research.