Amongst US patients on the TriNetX platform, 32,489,776 were non-Hispanic Whites, including 17,111,169 (52.7%) females. The non-Hispanic Black population accounted for 8,702,848 individuals, 4,654,839 (53.5%) females. In the White group, 708,004 individuals (2.18%) were diagnosed with ADHD. Out of those, 313,138 (44.2%) were females. Additionally, 110,160 (0.34%) were diagnosed with ODD or CD, and 36,300 (33%) were females. In the Black group, 141,277 (1.62%) were diagnosed with ADHD, including 51,323 (36.3%) females and 47,437 (0.55%) were diagnosed with ODD or CD, including 17,047 (35.9%) females. The incidences of each diagnosis and its associated presentations in each race and sex cohort were normalized by their population, then by the White cohort for racial analysis and the White male cohort for the sex analysis (Figures S2 & S3; Table S1).
In Figure 1a, apart from ADHD hyperactive type (ADHD-HT), ADHD diagnoses are significantly less prevalent in the Black population than in the White population. In the total ADHD cohort, a diagnosis in the Black population is 26% (OR, 0.74; 95% CI, 0.73-0.74; P<0.0001) less prevalent than in Whites. ADHD inattentive-type (ADHD-IT) is 55% (OR, 0.45; 95% CI, 0.45-0.46; P<0.0001) less prevalent in the Black population, while ADHD-HT is 0.03% (OR, 1.03; 95% CI, 1.01-1.05; P = 0.007) more prevalent in the Black population, although this result is not clinically significant. For ADHD combined-type (ADHD-CT) and unspecified ADHD, a diagnosis is, respectively, 13% (OR, 0.87; 95% CI, 0.86-0.88; P<0.0001) and 17% (OR, 0.83; 95% CI, 0.82-0.84; P<0.0001) less prevalent in the Black population than in the White population.
In Figure 1b, CD diagnoses are more prevalent in the Black population than in the White population. In the total CD cohort, a diagnosis in the Black population is 61% (OR, 1.61; 95% CI, 1.59-1.63; P<0.0001) more prevalent than in the White population, while ODD is 35% (OR, 1.35; 95% CI, 1.33-1.37; P<0.0001) more prevalent. Childhood-onset CD and adolescent-onset CD are, respectively, 128% (OR, 2.28; 95% CI, 2.21-2.37; P<0.0001) and 73% (OR, 1.73; 95% CI, 1.56-1.92; P<0.0001) more prevalent in the Black population while unspecified CD was 78% (OR, 1.78; 95% CI, 1.76-1.81; P<0.0001) more prevalent than in the White population. Figure 1c shows the odds ratio and 95% confidence interval for the differences in the incidence for each disorder cohort and its presentations with the exact values listed in Table 1.
Table 1: Fisher's Exact Test comparing the prevalence of ADHD and its presentations and CD and its presentations between the Black and White populations.
|
Number of Black Patients
|
Number of White Patients
|
Odds Ratio
|
95 % Confidence Interval
|
p-value
|
Total ADHD
|
141,277
|
708,004
|
0.74
|
0.73-0.74
|
<0.0001
|
Predominantly Inattentive
|
24,047
|
197,246
|
0.45
|
0.45-0.46
|
<0.0001
|
Predominantly Hyperactive
|
9,416
|
34,073
|
1.03
|
1.01-1.05
|
0.007
|
Combined ADHD
|
53,895
|
230,083
|
0.87
|
0.86-0.88
|
<0.0001
|
Unspecified ADHD
|
107,660
|
482,871
|
0.83
|
0.82-0.84
|
<0.0001
|
Total CD
|
47,437
|
110,160
|
1.61
|
1.59-1.63
|
<0.0001
|
ODD
|
17,826
|
49,248
|
1.35
|
1.33-1.37
|
<0.0001
|
Childhood-onset CD
|
4,698
|
7,673
|
2.28
|
2.21-2.37
|
<0.0001
|
Adolescent-onset CD
|
530
|
1,140
|
1.73
|
1.56-1.92
|
<0.0001
|
Unspecified CD
|
34,590
|
72,490
|
1.78
|
1.76-1.81
|
<0.0001
|
The AoD for each cohort was calculated, and we discovered that the average ADHD AoD of White patients is 23.9, which is significantly higher than the average ADHD AoD of Black patients at 15.7 (95% CI, 8.1-8.24; P < 0.0001), attributed to the relative increase in the diagnosis of Whites between the ages of 18 and 40 years old (Figure 2a; Table S2). Linear regression analysis resulted in a correlation coefficient of 0.86 between the AoD of ADHD in Black versus White patients (Figure S4A). However, a linear regression performed on a subset of patients 18 years old or younger yielded a higher correlation coefficient of 0.97 (Figure S4B). These data suggest that the AoD between Blacks and Whites with ADHD are essentially the same in childhood, yet there is a substantial increase in the diagnosis of ADHD in White adults compared to Blacks.
The AoD distribution of Black and White CD patients highlights more parallel trends between the two groups (Figure 2b). Linear regression analysis shows a high correlation between AoD in CD cases in Black and White patients, with a coefficient of 0.97 (Figure S4C).
Figure 3a and Table 2 show that Black females are the most underrepresented group across sex and race, being 59% (OR, 0.41; 95% CI, 0.41-0.42; P < 0.0001) less prevalent than White males. White females diagnosed with ADHD are 31% (OR, 0.69; 95% CI, 0.69-0.70; P < 0.0001) less prevalent, while Black males are 12% (OR, 0.88; 95% CI, 0.87-0.89; P < 0.0001) less prevalent. With ADHD-IT diagnosis in the Black male population is 47% (OR, 0.53; 95% CI, 0.52-0.54; P < 0.0001) less prevalent than the White male population, while diagnosis in the Black female population is 63% (OR, 0.37; 95% CI, 0.36-0.37; P < 0.0001) less prevalent. With ADHD-IT prevalence of diagnosis in Black males are 16% (OR, 1.16; 95% CI, 1.12-1.19; P < 0.0001) higher than in White males, while in Black females and White females, the prevalence of diagnosis is, respectively, 61% (OR, 0.39; 95% CI, 0.37-0.40; P < 0.0001) and 55% (OR, 0.45; 95% CI, 0.44-0.46; P < 0.0001) less. The prevalence of ADHD-CT diagnosis in Black females and White females are, respectively, 63% (OR, 0.37; 95% CI, 0.36-0.37; P < 0.0001) and 48% (OR, 0.52; 95% CI, 0.51-0.52; P < 0.0001) less than in White males. Unspecified ADHD diagnosis is 54% (OR, 0.46; 95% CI, 0.45-0.47; P < 0.0001) less in Black females, and 31% (OR, 0.69; 95% CI, 0.69-0.70; P < 0.0001) less in White females compared to White males.
Table 2: Fisher's Exact Test comparing the prevalence of ADHD and its presentations in each of the Black Female, Black Male and White Female populations to their prevalence in the White Male population.
|
Cohort
|
Number of Patients
|
Odds Ratio
|
95% Confidence Interval
|
p-value
|
Total ADHD
|
Black Female
|
51,323
|
0.41
|
0.41 - 0.42
|
<0.0001
|
Black Male
|
89,935
|
0.88
|
0.87 - 0.89
|
<0.0001
|
White Female
|
313,138
|
0.69
|
0.69 - 0.70
|
<0.0001
|
White Male
|
394,607
|
NA
|
Predominantly Inattentive ADHD
|
Black Female
|
10,790
|
0.37
|
0.36 - 0.37
|
<0.0001
|
Black Male
|
12,953
|
0.53
|
0.52 - 0.54
|
<0.0001
|
White Female
|
100,539
|
0.93
|
0.92 - 0.94
|
<0.0001
|
White Male
|
94,857
|
NA
|
Predominantly Hyperactive ADHD
|
Black Female
|
2,680
|
0.39
|
0.37 - 0.40
|
<0.0001
|
Black Male
|
6,680
|
1.16
|
1.12 - 1.19
|
<0.0001
|
White Female
|
11,558
|
0.45
|
0.44 - 0.46
|
<0.0001
|
White Male
|
22,345
|
NA
|
Combined ADHD
|
Black Female
|
16,424
|
0.37
|
0.36 - 0.37
|
<0.0001
|
Black Male
|
36,983
|
0.99
|
0.98 - 1.01
|
0.62
|
White Female
|
84,691
|
0.52
|
0.51 - 0.52
|
<0.0001
|
White Male
|
143,452
|
NA
|
Unspecified ADHD
|
Black Female
|
38,154
|
0.46
|
0.45 - 0.47
|
<0.0001
|
Black Male
|
66,593
|
0.97
|
0.96 - 0.98
|
<0.0001
|
White Female
|
211,128
|
0.69
|
0.69 - 0.70
|
<0.0001
|
White Male
|
264,589
|
NA
|
Figure 3b and Table 3 shows that compared to the White male population, total Black male CD diagnosis is 59% (OR, 1.59; 95% CI, 1.57-1.62; P < 0.0001) higher, while in Black females it is 25% (OR, 0.75; 95% CI, 0.73-0.76; P < 0.0001) less and in White females it is 57% (OR, 0.43; 95% CI, 0.42-0.44; P < 0.0001) less. ODD diagnosis in Black males is 29% (OR, 1.29; 95% CI, 1.26-1.32; P < 0.0001) more prevalent than in White males, but 39% (OR, 0.61; 95% CI, 0.59-0.63; P < 0.0001) less prevalent in Black females and 59% (OR, 0.41; 95% CI, 0.40-0.41; P < 0.0001) less prevalent in White females. Childhood-onset CD is 119% (OR, 2.19; 95% CI, 2.10-2.29; P < 0.0001) more prevalent in Black males and 64% (OR, 0.36; 95% CI, 0.34-0.38; P < 0.0001) less overall in White females than in White males. As for adolescent-onset CD, Black males have a 65% (OR, 1.65; 95% CI, 1.44-1.89; P < 0.0001) higher diagnosis prevalence, and White females have a 53% (OR, 0.47; 95% CI, 0.42-0.54; P < 0.0001) lower diagnosis prevalence than White males. Unspecified CD is 78% (OR, 1.78; 95% CI, 1.75-1.81; P < 0.0001) more prevalent in Black males, 19% (OR, 0.81; 95% CI, 0.79-0.82; P < 0.0001) less prevalent in Black females and 57% (OR, 0.43; 95% CI, 0.42-0.44; P < 0.0001) less prevalent in White females, all compared to prevalence in White males.
The odds ratio and 95% confidence interval for the prevalence differences in ADHD, CD, and their presentations of each race and sex cohort are plotted in Figure S5 comparing A. Black male, B. White female, and C. Black female, all to White male. Pearson’s Chi-squared test results show a significant association between the categories of race and sex in each disorder (Table S3).
Table 3: Fisher's Exact Test comparing the prevalence of CD and its presentations in each of the Black Female, Black Male and White Female populations to their prevalence in the White Male population.
|
Cohort
|
Number of Patients
|
Odds Ratio
|
95% Confidence Interval
|
p-value
|
Total CD
|
Black Female
|
17,047
|
0.75
|
0.73 - 0.76
|
<0.0001
|
Black Male
|
30,381
|
1.59
|
1.57 - 1.62
|
<0.0001
|
White Female
|
36,300
|
0.43
|
0.42 - 0.44
|
<0.0001
|
White Male
|
73,837
|
NA
|
ODD
|
Black Female
|
6,256
|
0.61
|
0.59 - 0.63
|
<0.0001
|
Black Male
|
11,017
|
1.29
|
1.26 - 1.32
|
<0.0001
|
White Female
|
15,233
|
0.41
|
0.40 - 0.41
|
<0.0001
|
White Male
|
32,997
|
NA
|
Childhood-onset CD
|
Black Female
|
1,567
|
0.94
|
0.89 - 1.00
|
0.07
|
Black Male
|
3,037
|
2.19
|
2.10 - 2.29
|
<0.0001
|
White Female
|
2,203
|
0.36
|
0.34 - 0.38
|
<0.0001
|
White Male
|
5,350
|
NA
|
Adolescent-onset CD
|
Black Female
|
200
|
0.91
|
0.77 - 1.06
|
0.26
|
Black Male
|
304
|
1.65
|
1.44 - 1.89
|
<0.0001
|
White Female
|
383
|
0.47
|
0.42 - 0.54
|
<0.0001
|
White Male
|
712
|
NA
|
Unspecified CD
|
Black Female
|
11,915
|
0.81
|
0.79 - 0.82
|
<0.0001
|
Black Male
|
21,987
|
1.78
|
1.75 - 1.81
|
<0.0001
|
White Female
|
23,528
|
0.43
|
0.42 - 0.44
|
<0.0001
|
White Male
|
47,730
|
NA
|