Abstract
BACKGROUND: Lower socioeconomic position (SEP) is a risk factor for poor-quality end-of-life cancer care, but mechanisms of this disparity are not fully understood. We investigated whether receipt of specialised palliative care (SPC) mediates the effect of SEP on end-of-life cancer care quality outcomes. METHODS: This cohort study included all adults who died with cancer from 2015 to 2021, in Ontario, Canada. We performed a mediation analysis using material deprivation as a measure of SEP, classified into quintiles from least (Q1) to most deprived (Q5). End-of-life outcomes included receipt of systemic anticancer treatment (SACT) and high health services use (≥2 emergency department visits, ≥2 hospitalisations, ≥1 intensive care unit admission) in the last 30 days of life, and home death. Generalised linear models estimated the adjusted odds ratio (aOR) for each outcome, and direct effect of SEP, and the indirect effect via SPC, across each quintile (Q1 = reference). FINDINGS: Among 173,915 patients, SPC mediated the effects of SEP on end-of-life outcomes. Compared to Q1, patients in Q2-Q5 were progressively less likely to receive SACT at end-of-life (aOR [95% CI], Q3: 0.89 [0.84-0.93]; Q5: 0.77 [0.74-0.81]), or to die at home (Q3: 0.90 [0.87-0.93]; Q5: 0.78 [0.76-0.81]); lack of SPC partially mediated these effects, blunting the effect on SACT and augmenting the effect on home deaths. Compared to Q1, patients in Q2 to 5 were more likely to experience high health services use (Q3: 1.06 [1.02-1.10]; Q5: 1.12 [1.08-1.16]); lack of SPC fully mediated this effect, driven by increasing likelihood of multiple emergency department visits in more deprived quintiles. INTERPRETATION: Receipt of SPC mediated the effects of SEP on end-of-life quality outcomes. Equitable access to SPC for all patients with cancer may mitigate these disparities. FUNDING: This study was supported by an Operating Grant from the Canadian Institutes of Health Research (Dr. Zimmermann), the Harold and Shirley Lederman Chair in Palliative Care and Psychosocial Oncology (Grant number MM1-174912; Dr. Zimmermann), a Doctoral Research Award: Canada Graduate Scholarship (Grant number FBD-181354; Dr. Iqbal) from the Canadian Institutes of Health Research (CIHR), and a Peterborough KM Hunter Charitable Foundation Graduate Award in Cancer Research (Dr. Iqbal).