Table 1.

Characteristics of patients in discovery and validation cohorts

Variable	Discovery total	Discovery cohort 1	Discovery cohort 2	Discovery cohort 3	Discovery cohort 4	Validation
No of patients (after QC)	113 (106)	12 (11)	20 (17)	11 (10)	70 (68)	60 (60)
Osteoarthritis joint	Knee or hip	Knee	Knee	Hip	Knee	Knee
Low-grade OA cartilage samples after QC	87	11	16	10	50	60
High-grade OA cartilage samples after QC	95	10	16	10	59	–
Synovium samples after QC	77	–	16	–	61	–
Females, n (%) after QC	63 (59)	2 (19)	12 (71)	8 (73)	41 (60)	27 (45)
Age, average years (range) after QC	69 (38–88)	69 (50–88)	70 (54–79)	61 (44–88)	70 (38–84)	72 (63–85)

OA, osteoarthritis; QC, quality control.