Video-assisted thoracoscopic surgery (VATS) lobectomy is a commonly employed surgical technique for the management of operable early stage non-small cell lung cancer (NSCLC). This procedure, however, is dependent on the patient’s ability to tolerate surgery. In light of this, stereotactic ablative radiotherapy (SABR) has emerged as a viable alternative treatment strategy for patients who are inoperable or who refuse surgery. Considering the lack of randomised controlled trials and the increased risk of bias in observational cohort studies, this study protocol proposes an emulated target trial design to investigate the causal effect of SABR, in comparison to VATS, on overall survival in operable early stage NSCLC patients.

Data on NSCLC patients will be collected from routinely collected university hospital records linked with German cancer registry data. This study protocol was developed using the target trial methodology outlined by Hernan et al. The protocol establishes specific parameters for key trial components in order to mitigate bias in the analysis of observational data and to facilitate the calculation of causal estimands. The target trial design that would be emulated is a multicentre open-label two-parallel arm superiority randomised trial. Mediators and confounding variables were determined through the use of a directed acyclic graph. The statistical analysis aims to measure the per-protocol and intention to treat effect of SABR versus VATS within 3 months of diagnosis, on survival, through the difference in restricted mean survival times, using weighted non-parametric Kaplan-Meier curves.

The Ethics Committee of the Medical Faculty of Martin Luther University Halle-Wittenberg with an approved addendum with Dnr 2023–112 has approved this study. The study uses anonymised routinely collected hospital and cancer registry data in accordance with applicable data protection regulations. Results will be disseminated through peer-reviewed publications and presentations at scientific conferences.

To examine how socioeconomic deprivation influences referral pathways to emergency departments (EDs) and to assess how these pathways affect subsequent hospital outcomes.

Retrospective observational study.

Emergency department of a large teaching hospital in the East of England, providing secondary and tertiary care.

482 787 ED attendances by patients aged 16 years and over, recorded between January 2019 and December 2023. Patients were assigned Index of Multiple Deprivation (IMD) deciles based on residential postcode.

Referral source (general practitioner (GP), National Health Service (NHS) 111, ambulance, self-referral, other), total ED time, 4-hour breach, hospital admission and unplanned return within 72 hours.

Substantial socioeconomic inequalities were observed in referral pathways. Patients from the most deprived areas were significantly less likely to be referred by a GP (4.7%) than those from the least deprived areas (14.7%) and more likely to arrive via ambulance (32% vs 24%). These differences persisted after adjusting for demographic, clinical and contextual variables. Ambulance referrals showed the longest ED stays, ranging from 347 to 351 min across IMD deciles (overall 95% CI 343 to 363) and the highest probability of 4-hour breaches (51%; 95% CI 50% to 53%). Self-referrals had the greatest rates of unplanned returns within 7 days (up to 7.1%; 95% CI 5.5% to 8.7%). In contrast, NHS 111 and GP referrals were associated with shorter stays, lower breach rates and fewer reattendances. Minimal variation in outcomes was observed across deprivation levels once referral source was accounted for.

Inequalities in how patients access emergency care, particularly reduced GP and NHS 111 referrals among more deprived groups, appear to underpin disparities in ED outcomes. Referral source captures important clinical and system-level factors that influence patient experience and resource use. Interventions to improve equitable access to structured referral pathways, particularly in more deprived areas, may enhance both the efficiency and fairness of emergency care delivery. Further research using national data is needed to assess broader policy implications and economic costs associated with differential access.