Table 4.

Cascade testing metrics^a in FH^g− families by polygenic score quintile and DLCN score in probands

	FHg− Proband Polygenic Score Quintileb			FHg− Probandsc
Parameter With 95% CIs	Q5	Q1-Q4	P value	DLCN ≥6	DLCN <6	P value
Number of probands	22	51	–	36	37
Number of family members identified	93	202		150	145
Consented	19	56	–	41	34	–
Completed testing	18	45	–	35	28	–
Met criteria as a new case	7	10		11	6
Mean number of family members per proband	4.2 (3.0-5.4)	4.0 (3.3-4.7)	.702	4.2 (3.3-5.1)	3.9 (3.1-4.7)	.722
Consented	0.9 (0.5-1.4)	1.1 (0.7-1.5)	.444	1.1 (0.6-1.7)	0.9 (0.6-1.3)	.488
Completed testing	0.8 (0.5-1.3)	0.9 (0.5-1.2)	.848	1.0 (0.6-1.4)	0.8 (0.5-1.1)	.440
Met criteria as a new case	0.3 (0.1-0.6)	0.2 (0.1-0.3)	.280	0.3 (0.1-0.5)	0.2 (0.1-0.3)	.116
NCICd	0.32 (0.14-0.591)	0.19 (0.08-0.31)	.280	0.31 (0.14-0.50)	0.16 (0.05-0.29)	.116
Uptake of cascade testinge	19.4% (10.5-30.8)	22.3% (15.6-27.9)	.684	23.3% (14.7-33.1)	19.3% (12.9-25.3)	.404
Yield of cascade testingf	38.9% (17.6-71.4)	22.2% (11.6-32.6)	.176	31.4% (18.2-46.2)	21.4% (7.3-39.2)	.364

FH^g−, familial hypercholesterolemia without a pathogenic variant; LDL-C, low-density lipoprotein cholesterol; NCIC, new cases per index case.

^aNew case is defined as a family member with an LDL-C ≥155 mg/dL.

^bCIs were calculated using bootstrapping over 1000 iterations. Each bootstrap sample selected 22 probands with polygenic score quintile 5 or 51 probands with polygenic score quintiles 1 to 4 (simple random sampling with replacement) and their corresponding family members. Each parameter was calculated separately within each bootstrap sample and the 2.5th and 97.5th percentiles across all bootstrap samples defined the 95% CIs.

^cCIs were calculated using bootstrapping over 1000 iterations. Each bootstrap sample selected 36 probands with DLCN score ≥6 or 37 probands with DLCN score <6 (simple random sampling with replacement) and their corresponding family members.

^dNCIC was calculated as the number of family members who met criteria as a new case divided by the total number of probands.

^eUptake was defined as the proportion of family members who consented and completed testing among all identified family members.

^fYield was defined as the proportion of family members who met criteria as a new case among family members who consented and completed testing.