Table 2. Prevalence of Familial DCM in Probands, by Proband Self-reported Race and Ethnicity.
| Race and ethnicity group | Total | Familial DCM prevalence | |||
|---|---|---|---|---|---|
| Standard definitiona | Expanded definitiona | ||||
| Crude | Model-basedb | Crude | Model-basedb | ||
| No. (%) | % (95% CI) | No. (%) | % (95% CI) | ||
| All races and ethnicities | 1220 | 141 (11.6) | 29.7 (23.5-36.0) | 294 (24.1) | 56.9 (50.8-63.0) |
| All ethnicities | |||||
| Black | 526 | 57 (10.8) | 39.4 (29.9-48.8) | 104 (19.8) | 60.6 (52.4-68.7) |
| White | 694 | 84 (12.1) | 28.0 (21.4-34.6) | 190 (27.4) | 56.2 (49.7-62.7) |
| All races | |||||
| Hispanic | 102 | 13 (12.8) | 28.6 (14.1-43.1) | 26 (25.5) | 53.7 (40.0-67.3) |
| Non-Hispanic | 1118 | 128 (11.5) | 30.0 (23.7-36.2) | 268 (24.0) | 57.7 (51.4-63.9) |
| Hispanic | |||||
| Black | 10 | 1 (10) | 25.7 (0.0-68.3)c | 2 (20.0) | 45.0 (1.2-88.7) |
| White | 92 | 12 (13) | 28.8 (13.8-43.7) | 24 (26.1) | 54.1 (40.1-68.2) |
| Non-Hispanic | |||||
| Black | 516 | 56 (10.9) | 40.3 (30.8-49.9) | 102 (19.8) | 61.7 (53.7-69.7) |
| White | 602 | 72 (12.0) | 27.8 (21.2-34.5) | 166 (27.6) | 56.8 (50.1-63.5) |
Abbreviations: DCM, dilated cardiomyopathy; LVE, left ventricular enlargement; LVSD, left ventricular systolic dysfunction.
A proband has familial DCM if at least 1 living first-degree relative has DCM by the standard definition and if at least 1 living first-degree relative has DCM, LVSD, or LVE without known cause by the expanded definition.
Estimates from a beta-binomial mixed model (eTables 1 and 3 in Supplement 1; Supplement 2) were used to obtain marginally standardized estimates and delta method 95% CIs for familial DCM prevalence if all living first-degree relatives were screened. Probands without living or screened first-degree relatives provide no information on the parameters of interest in the likelihood; all model-based estimates were therefore derived from 822 probands (8 Hispanic Black, 64 Hispanic White, 290 non-Hispanic Black, 460 non-Hispanic White) with at least 1 screened first-degree relative. The reported estimates are for patients seen at a typical US advanced heart failure program, defined as a program at the mean or mode of the random effects distribution describing the population of such programs. Each patient subpopulation defined by race and ethnicity was assumed to be balanced across the 8 possible sex and age quartile combinations, and the number of living first-degree relatives was assumed to follow a Poisson distribution with a mean of 4.53, which was the mean number of living first-degree relatives per family in the cohort. In subpopulations containing multiple race and ethnicity groups, constituent groups were represented in proportion to 2019 US Census population estimates for the groups of interest (All races and ethnicities: 0.99% Hispanic Black, 13.97% non-Hispanic Black, 18.06% Hispanic White, 66.98% non-Hispanic White; All ethnicities, Black: 6.64% Hispanic, 93.36% non-Hispanic; All ethnicities, White: 21.24% Hispanic, 78.76% non-Hispanic; All races, Hispanic: 5.21% Black, 94.79% White; All races, non-Hispanic: 17.26% Black, 82.74% White).
The actual lower bound of the 95% CI was negative and truncated at zero.