TABLE 2.

Comparison of a Research Cohort (pediatric sarcoma as training data) and a Clinical Cohort (clinical cancer genetics as validation data) on the Extent of Missing Age at Last Contact and Missing Age at Cancer Diagnoses at Both Family and Individual Levels

Summary Statistics	RPB Training Data	CCB Validation Data
No. of families
All family members, No. (%)
Complete data	189 (100)	10 (8)
Missing age at last contact only	0 (0)	46 (37)
Missing age at cancer diagnosis only	0 (0)	0 (0)
Missing both age at last contact and age at cancer diagnosis	0 (0)	68 (55)
Total	189	124
Chi-square test	P < .001
First-degree relatives and spouse only, No. (%)
Complete data	189 (100)	68 (55)
Missing age at last contact only	0 (0)	41 (33)
Missing age at cancer diagnosis only	0 (0)	10 (8)
Missing both age at last contact and age at cancer diagnosis	0 (0)	5 (4)
Total	189	124
Chi-square test	P < .001
No. of individuals
All family members, No. (%)
Complete data	3,706 (100)	1,748 (53)
Missing age at last contact only	0 (0)	1,339 (41)
Missing age at cancer diagnosis only	0 (0)	138 (4)
Missing both age at last contact and age at cancer diagnosis	0 (0)	72 (2)
Total	3,706	3,297
Chi-square test	P < .001
First-degree relatives and spouse only, No. (%)
Complete data	1,126 (100)	487 (79)
Missing age at last contact only	0 (0)	105 (17)
Missing age at cancer diagnosis only	0 (0)	19 (3)
Missing both age at last contact and age at cancer diagnosis	0 (0)	2 (0.3)
Total	1,126	613
Chi-square test	P < .001
No. of individuals per family
Min	3	1
5th percentile	4	1
10th percentile	5	4
25th percentile	6	16
Median	7	27
Mean	20	27
75th percentile	10	36
90th percentile	15	48
95th percentile	72	54
Max	719	75

NOTE. Summary statistics for the number of individuals per family are reported to contrast the depth of data collection procedures in research and clinical cohorts as they happen in the unit of families.

Abbreviations: CCB, clinical counseling-based; RPB, research protocol-based.