Abstract
Historically, cancers diagnosed via the emergency department (ED) portend a poor prognosis. Recent data from the United States are sparse, and analyses of cancers detected in the years following ED visits are lacking. Thus, we analyzed data from nine rural U.S. Midwest counties included within the population-based Rochester Epidemiology Project (2015-2021). Participants without a history of cancer (N = 42,074) who did not receive ED care were matched 1:1 to ED participants on the date of ED visit, age, sex, race, ethnicity, and county of residence. Analyses were restricted to participants with records ≤2 years prior to ED or index visit and ≥30 days after. HRs and 95% confidence intervals (CI) comparing cancer incidence and deaths among ED and non-ED participants were estimated from Cox proportional hazards regression models, either unadjusted or adjusted for covariates. Cumulative cancer incidence curves accounting for competing risks of death and survival (all cause and cancer-specific) were estimated. The median follow-up was 6.3 years, with 2,719 (6.46%) cancers diagnosed among ED participants and 3,139 (7.46%) among non-ED participants. ED participants experienced lower cancer risk overall (HRAdjusted = 0.70; 95% CI, 0.66-0.74; P = 8.89 × 10-31), specifically for breast cancer, prostate cancer, melanoma, and secondary cancers. Cancer-specific mortality was higher among ED participants (HRAdjusted = 1.76; 95% CI, 1.49-2.08; P = 3.62 × 10-11). Compared with non-ED participants, ED participants experienced a lower incidence of cancer but higher overall cancer-specific mortality, suggesting that subsets of ED patients may benefit from postvisit preventive interventions. PREVENTION RELEVANCE: This cohort analysis shows that cancer incidence over 6 years was lower among participants after an ED visit than among matched non-ED participants, whereas cancer-specific mortality was higher in the ED group (HRAdjusted = 1.76; 95% CI, 1.49-2.08; P = 3.62 × 10-11), suggesting the potential benefit of preventive interventions.