Cindy Boer

Hand Osteoarthritis Phenotypes | 97 2.2 Table 1: General Characteristics of the study population Cohort RS-I RS-II RS-III Hand n (OA cases) 4,829 (1,830) 1,791 (688) 2,071 (526) Female (%) 2773 (0.57) 964 (0.54) 1180 (0.57) Age (sd) 67.6(7.9) 64.6(7.9) 57.1(7.0) Klsum (aver.(sd)) 8.4 (9.9) 6.9 (4.0) 4.7 (6.5) Osteophytes (aver.(sd)) 7.1 (7.8) 6.8 (8.2) 4.6 (6.3) JSN (aver.(sd)) 0.84 (2.4) 0.34 (1.3) 0.2 (0.8) Finger n (OA cases) 4,839 (1,244) 1,803 (474) 2,072 (298) Female (%) 2779 (0.57) 972 (0.54) 1181 (0.57) Age (sd) 67.6(7.9) 64.6(7.9) 57.1(7.0) Klsum (aver.(sd)) 5.8 (7.4) 4.5 (6.1) 3.0 (4.7) Osteophytes (aver.(sd)) 4.7 (5.5) 4.3 (5.8) 2.9 (4.5) JSN (aver.(sd)) 0.6 (1.9) 0.25 (1.1) 0.1 (0.7) Thumb n (OA cases) 4,882 (916) 1,813 (255) 2,083 (166) Female (%) 2785 (0.57) 972 (0.54) 1184 (0.57) Age (sd) 67.6(7.9) 64.6(7.9) 57.1(7.0) Klsum (aver.(sd)) 2.1 (3.3) 1.2 (2.3) 0.8 (1.7) Osteophytes (aver.(sd)) 1.3 (2.1) 0.93 (1.7) 0.6 (1.3) JSN (aver.(sd)) 0.4 (1.0) 0.18 (0.63) 0.1 (0.4) OA: osteoarthritis, KL: Kellgren-Lawerence, JSN: joint space narrowing, aver.: average, sd: standard de- viation, RS: Rotterdam Study Detailed phenotype descriptions For each participant, all hand joints (16 joints per hand, 32 joints per individual) were scored for Kellgren and Lawrence (KL) grade[31] based on hand radiographs. KL grade is a semi-quantitative score ranging from 0-4, where higher scores indicate more severe disease. Radiographic OA was defined as KL-grade ≥2 (definite joint space narrowing and definite osteophytes). Each joint was also scored for individual radiographic fea- tures including joint space narrowing (JSN) and osteophytosis (OST)[31]. The JSN and OST scores are semi-quantitative scores ranging from 0-3, where 0=none, 1=possible, 2=definite and 3=marked. We conducted hierarchical clustering of KL grade across all hand joints to identi- fy patterns of disease occurrence defined by location and disease severity (see online supplementary text). This yielded three semi-quantitative hand OA phenotypes for analysis: 1) hand KLsum=sum of KL grades across all DIP, PIP, MCP, IP, and CMC1 joints in both hands (15 joints per hand, 30 joints per individual, hand KLsum score range: 0 - 120), 2) finger KLsum=sum of KL grades across all DIP and PIP joints in both hands