Cancer patients as frequent attenders in emergency departments: A national cohort study

Background: Cancer patients contribute significantly to emergency department (ED) utilization. The objective of this study was to identify factors associated with patients becoming ED frequent attenders (FA) after a cancer-related hospitalization. Methods: A retrospective cohort study was conducted using national administrative, billing, and death records of Singapore residents discharged alive from Singapore public hospitals from January 2012 to December 2015, with a primary discharge diagnosis of cancer. Patients with four or more ED visits within any 12-month period after discharge from their index hospitalization were classified as FA. Time to FA distribution was estimated using the Kaplan-Meier method, and factors associated with risk of FA were identified using multivariate Cox regression analyses. Results: Records for 47 235 patients were analyzed, of whom 2980 patients were FA within the study period. Age (<17 years, hazard ratio [HR] 2.92, 95% CI 2.28-3.74; 75-84 years, HR 1.29, 95% CI 1.16-1.45; and >= 85 years, HR 1.71, 95% CI 1.45-2.02, relative to age 55-64), male gender (HR 1.26, 95% CI 1.16-1.37), Charlson comorbidity index (HR 1.21, 95% CI 1.19-1.23), and socioeconomic factors (Medi fund use, HR 1.40, 95% CI 1.23-1.59; housing subsidy type, HR 2.12, 95% CI 1.77-2.54) were associated with increased risk of FA. Primary malignancies associated with FA included brain and spine (HR 2.51, 95% CI 1.67-3.75), head and neck cancers (tongue, HR 2.05, 95% CI 1.27-3.31; hypopharynx, HR 2.72, 95% CI 1.56-4.74), lung (trachea and lung, HR 1.57, 95% CI 1.13-2.18; pleural, HR. 3.69, 95% CI 2.12-6.34), upper gastrointestinal (stomach, HR 1.93, 95% CI 1.26-2.74; esophagus, HR 4.13, 95% CI 2.78-6.13), hepato-pancreato-biliary (liver, HR 1.42, 95% CI 1.01-2.00, pancreas, HR 2.48, 95% CI 1.72-3.59), and certain hematological malignancies (diffuse non-Hodgkin's lymphoma, HR 1.59, 95% CI 1.08-2.33, lymphoid leukemia, HR 1.86, 95% CI 1.21-2.86). Brain (HR. 1.69, 95% CI 1.27-2.26), lung (HR 1.31, 95% CI 1.01-1.71), liver (HR 1.46, 95% CI 1.14-1.89), and bone (HR 1.35, 95% CI 1.04-1.76) metastases were also associated with FA. Conclusion: There are cancer-specific factors contributing to ED frequent attendance. Additional resources should be allocated to support high-risk groups and prevent unnecessary ED use.