Barriers and facilitators of implementing a lung cancer screening initiative in Singapore: a mixed-methods implementation research study using the i-PARIHS framework

Lung cancer is a leading cause of cancer-related mortality in Singapore, with over 60% of cases diagnosed at advanced stages. The local epidemiology, characterised by a high proportion of never-smokers, highlights a significant gap in the applicability of Western-centric screening models. To address this, the SingapOre Lung cancer Screening Through Integrating CT with other biomarkErs (SOLSTICE) initiative was launched, adapting low-dose computed tomography (LDCT) screening for both smokers and at-risk never-smokers. This study evaluates the implementation of the SOLSTICE pilot programme, guided by the Integrated Promoting Action on Research Implementation in Health Services (i-PARIHS) framework. Objectives were to identify barriers and facilitators to implementation and determine strategies for national scale-up. A convergent mixed-methods study was conducted within SingHealth, a healthcare cluster in Singapore. Data collection included a stakeholder workshop ( n = 17), key informant interviews ( n = 10), a provider survey ( n = 25) and a feedback survey with screening participants ( n = 71). Qualitative data were thematically analysed, and quantitative data were analysed using descriptive statistics. LDCT screening was valued but operationally complex, with incidental findings in approximately 78% of participants, substantially increasing reporting and follow-up workload. To address these challenges, adaptations such as an internal standardised nodule management protocol and weekly multidisciplinary meetings were implemented. Participants reported high acceptability (96%) and increased knowledge, but cited cost and logistics as potential barriers. Providers supported screening but cited additional workload and inconsistent knowledge of eligibility criteria, highlighting the need for dedicated coordinators and greater primary care involvement. Supportive organisational culture and leadership facilitated implementation, but gaps in measurement systems and staffing persisted. Externally, the lack of national policy, sustainable funding, and low public awareness were seen as key obstacles to scaling up. Stakeholders prioritised subsidies, public awareness campaigns, policy endorsement, provider training, and stronger primary care referral pathways. Embedded facilitation enabled real-time feedback and adaptations, but could not substitute for absent policy and financing. The SOLSTICE pilot demonstrated acceptability and value for participants and providers, but systemic and structural barriers challenge sustainability. For lung cancer screening to become a sustainable public health service in Singapore, system-level changes, particularly in policy, financing, and delivery infrastructure, are essential.