Mortality after emergency presentation: evidence from a cohort of 929 378 Medicare beneficiaries with common cancers diagnosed 2008-2017.

Abstract

Emergency presentation (EP) for cancer diagnosis is associated with higher mortality, but prior research has largely focused on select cancer types or non-U.S. populations. We estimated EP prevalence and associated mortality across 16 cancers in a national Medicare cohort. Using SEER-Medicare data, we identified patients with 16 high-burden cancers diagnosed 2008-2017. EP was defined by an ED claim within 30 days before the index cancer claim and subtyped as inpatient EP (emergency hospitalization) or outpatient EP (following ED discharge). We estimated survival probabilities and mortality risk ratios (RRs) adjusted for demographics, tumor characteristics, comorbidity, frailty, and healthcare utilization. Among 929,378 patients, 28% were EPs (22% inpatient, 6% outpatient). EP prevalence ranged from <10% (breast, prostate) to > 40% (liver, lung, stomach, colon, ovarian, pancreatic cancers). One-year survival was 81% for non-EPs, 60% for outpatient EPs, and 36% for inpatient EPs. Compared with non-EPs, inpatient EPs had nearly 4-fold higher 30-day adjusted mortality (RR = 3.88, 95% CI: 3.81-3.96), ranging from 2.1 (pancreas) to 6.3 (lymphoma). Among 90-day survivors, inpatient EPs had 51% higher one-year mortality (RR = 1.51, 1.49-1.52), ranging from 1.1 (pancreas) to 2.1 (lymphoma). Outpatient EPs showed intermediate risk (one-year mortality RR = 1.28, 1.26-1.30). EP is common and predicts persistently elevated mortality in older U.S. adults after comprehensive covariate adjustment. Associations were strongest for cancer types underrepresented in prior research, including hematologic malignancies, breast, prostate, and bladder cancers. Routine EP monitoring could improve risk stratification at diagnosis and guide efforts to reduce avoidable emergency presentations.