Race impacts the incidence of complicated appendicitis with abscess in urban populations but not in rural populations

Authors:
Manuel Castillo-Angeles, Reza Askari, Saba Ilkhani, Tandis Soltani

Body of Abstract:
Introduction:
Complicated appendicitis, characterized by generalized peritonitis and abscess formation, serves as a valuable “surgical access proxy,” with outcomes independently influenced by the timing of presentation, irrespective of care quality. Studies using nationally representative data suggest that Black patients are more likely to present with complicated appendicitis compared to White patients. Urbanicity also shapes these outcomes, with higher rates of complicated appendicitis presentations in rural areas. This study examines how racial disparities are influenced by rural versus urban settings.
Methods:
We analyzed data from the Nationwide Inpatient Sample (NIS) from 1990 to 2021, focusing on appendicitis cases. Among 1,218,245 cases of appendicitis, 14.5% were classified as complicated, involving generalized peritonitis and abscess formation. Multivariate logistic regression models were used to assess the impact of rural versus urban settings and racial disparities on complicated appendicitis, adjusting for age, gender, comorbidities, and insurance status. Secondary analyses examined urbanicity by transfer status and geographic region.
Results:
As expected, complicated appendicitis was more prevalent in rural areas compared to urban settings (14.7% vs. 13.9%, p< 0.001), and Black patients had a higher probability of complications compared to White patients (White: 14.8% [95% CI: 14.7–14.9], Black: 17.3% [95% CI: 17.1–17.6]). Urban areas exhibited significant racial disparities, with Black patients facing higher odds of complications compared to White patients (aOR = 1.05, 95% CI: 1.02–1.08, p = 0.001), while no significant racial disparities were observed in rural areas (aOR = 1.08, 95% CI: 0.96–1.22, p = 0.188). Stratification by transfer status revealed that among non-transferred patients, complication rates were similar between rural and urban settings (aOR = 0.97, p = 0.067). However, transferred patients in rural areas had significantly higher odds of complications (aOR = 1.21, 95% CI: 1.08–1.37, p = 0.005). Regional analysis showed higher complication rates in the rural Midwest and South but no significant differences in the West and Northeast. Conclusions: Our findings indicate that rural areas experience higher rates of complicated appendicitis, but racial disparities in these settings are absent, likely due to shared geographic barriers that affect all populations equally. In contrast, urban areas exhibit significant racial disparities. The lack of significant differences in complication rates among non-transferred rural patients underscores the critical role of timely access over the quality of care in determining outcomes. Addressing system-level inequities in urban settings and expanding healthcare infrastructure, particularly in vulnerable regions, is essential for achieving equitable patient outcomes.