High mortality due to sepsis in Native Hawaiians and African Americans: The Multiethnic Cohort

Sepsis is a severe systemic response to infection with a high mortality rate. A higher incidence has been reported for older people, in persons with a compromised immune system including cancer patients, and in ethnic minorities. We analyzed sepsis mortality and its predictors by ethnicity in the Multiethnic Cohort (MEC).

Among 191,561 white, African American, Native Hawaiian, Japanese American, and Latino cohort members, 49,347 deaths due to all causes and 345 deaths due to sepsis were recorded during follow-up from 1993-96 until 2010. Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated and adjusted for relevant confounders. In addition, national death rates were analyzed to compare mortality by state.

Age-adjusted rates of sepsis death were 5-times higher for Hawaii than Los Angeles (14.4 vs. 2.7 per 100,000). By ethnicity, Native Hawaiians had the highest rate in Hawaii (29.0 per 100,000) and African Americans in Los Angeles (5.2 per 100,000). In fully adjusted models, place of residence was the most important predictor of sepsis mortality (HR = 7.18; 95%CI: 4.37-11.81 Hawaii vs. Los Angeles). African Americans showed the highest risk (HR = 2.08; 95% CI: 1.16-3.75) followed by Native Hawaiians (HR = 1.88; 95% CI: 1.34-2.65) as compared to whites. Among cohort members with cancer (N = 49,794), the 2-fold higher sepsis mortality remained significant in Native Hawaiians only. The geographic and ethnic differences in the MEC agreed with results for national death data.

The finding that African Americans and Native Hawaiians experience a higher mortality risk due to sepsis than other ethnic groups suggest ethnicity-related biological factors in the predisposition of cancer patients and other immune-compromising conditions to develop sepsis, but regional differences in health care access and death coding may also be important.