Effect of proximity to specialty care on outcomes for biliary cancers: a population-based retrospective cohort study

The management of biliary cancers is complex and requires a multidisciplinary approach. Because it is unknown how access to specialty care affects resource use and survival in patients with biliary cancer, we conducted a population-based study to understand the needs of these patients and the relation of geography to care delivery and clinical outcomes for biliary cancer in Alberta.

All patients with biliary cancer diagnosed in Alberta from Sept. 1, 2001, to Dec. 31, 2015 were included in this population-based retrospective cohort study. Data were extracted from administrative databases and the 2011 Canadian census. Driving time and types of medical services were tracked throughout the patients' clinical course. We categorized proximity to specialty care according to driving time to the nearest specialist. The primary outcome was overall survival. We conducted Cox proportional hazard regression to evaluate the effects of driving time on overall survival and multivariate logistic regression to evaluate the effect of driving time on treatment types and stage at diagnosis.

We identified 1610 patients with biliary cancer; they accounted for 117 381 medical encounters. Patients living 120 minutes or more from the nearest hepatobiliary surgeon and from the nearest cancer centre had significantly decreased survival (hazard ratio [and 95% confidence interval (CI)] 1.27 [1.17-1.37]) and 1.27 [1.14-1.41], respectively). Location of residence was not associated with advanced stage or probability of undergoing surgery or a biliary drainage procedure. Patients who lived 120 minutes or more from a cancer centre were less likely than those who lived less than 120 minutes away to receive chemotherapy (odds ratio 0.51, 95% CI 0.29-0.88). Subgroup analysis showed that the effect of travel time was especially pronounced among those who received only best supportive care and those who had biliary drains.

Geography and accessibility to specialty care affected survival in patients with biliary cancer. Further study is required to understand how patients with biliary drains and those receiving best supportive care are affected by proximity to specialty care. This will aid in the identification of strategies to provide improved care for this subgroup who are particularly affected by geography.