Table 2.

Standardized Incidence Rates and Estimated Number of Newly Diagnosed Individuals With Anti-NMDAR Encephalitis Annually in the United States by Race/Ethnicity

Race/ethnicity	Cases with anti-NMDAR encephalitis	Active KPSC member person-years	Crude incidence per 1,000,000 person-years (95% CI)	Standardized incidence per 1,000,000 person-years (95% CI)a	US population in 2020b	Expected newly diagnosed patients with anti-NMDAR encephalitis annually
White	6	15,838,182	0.38 (0.08–0.68)	0.40 (0.08–0.72)	191,722,195	77
Hispanic	42	20,126,744	2.09 (1.46–2.72)	2.17 (1.51–2.83)	65,329,087	142
Black	12	4,074,294	2.95 (1.28–4.61)	2.94 (1.27–4.61)	39,944,624	117
Asian/Pacific Islander	10	5,390,568	1.86 (0.71–3.01)	2.02 (0.77–3.28)	20,243,574	41
Totalc	70	45,429,789	1.54 (1.18–1.90)	—	317,239,480	377

Abbreviations: KPSC = Kaiser Permanente Southern California; NMDAR = N-methyl-d-aspartate receptor.

^aStandardized to the 2020 US Census and adjusted for age and sex.

^bPer 2020 US Census.

^cIncludes persons with other/missing/unknown race and ethnicity.