. 2023 Mar 1;159(4):419–423. doi: 10.1001/jamadermatol.2023.0016

Table 2. Prevalence Ratios for Alopecia Areata, Alopecia Totalis, and Alopecia Universalis by Age, Sex, and Race and Ethnicity.

Comparison group	Standardized prevalence ratio (95% CI)^a
	Alopecia areata (all types)		Alopecia totalis/alopecia universalis (combined)
	>1 diagnosis	>2 diagnoses	Alopecia totalis/alopecia universalis (combined)
Sex
Female	1.32 (1.19-1.46)	1.30 (1.11-1.52)	2.63 (1.74-3.97)
Male	1 [Reference]	1 [Reference]	1 [Reference]
Age, y
Adult (≥18)	1.73 (1.53-1.97)	2.26 (1.82-2.81)	1.47 (0.94-2.28)
Pediatric (0-17)	1 [Reference]	1 [Reference]	1 [Reference]
Race and ethnicity
Asian	2.47 (2.17-2.81)	3.10 (2.61-3.68)	NA^b
Black	1.35 (1.26-1.44)	1.18 (1.07-1.32)	NA^b
Hispanic/Latino	1.26 (1.03-1.55)	NA^b	NA^b
White	1 [Reference]	1 [Reference]
Other/multiracial	1.87 (1.72-2.03)	1.83 (1.62-2.06)	NA^b

Abbreviation: NA, not applicable.

^{^a}

Confidence intervals for standardized prevalence ratios are based on the lognormal distribution.

^{^b}

Prevalence ratios were not computed due to the small number of cases within the subgroup. Standardized prevalence ratio is based on 10 AT cases in the subgroup of Black patients, and should be interpreted cautiously.