Table 1

 Baseline characteristics of the study population (n = 3906)

Female (%)58.3
Age (years) (mean (SD))66.6 (7.3)
+Hand disability (%)5.8
++Overall disability index (%)20.2
+Hand disability: mean score of 0.5 or more of various components composed of eight questions related to hand function on the Stanford health assessment questionnaire (HAQ).
++Overall disability index: mean score of 0.5 or more on HAQ index (scored 0 to 3).
*ROA: presence of K-L ⩾2 in at least one joint of the group.
†Hand ROA: presence of K-L ⩾2 in two of three groups (DIP, PIP, CMC1/TS).
CMC1/TS, first carpometacarpal plus trapezioscaphoid (base of thumb); DIP, distal interphalangeal; K-L, Kellgren–Lawrence radiological grade; MCP, metacarpophalangeal; PIP, proximal interphalangeal; ROA, radiographic osteoarthritis.
*ROA of DIP joints (%)47.338.634.8
*ROA of PIP joints (%)18.213.411.6
*ROA of MCP joints (%)
*ROA of CMC1/TS (%)35.825.830.2
†Hand ROA (%)28.321.520.6
Hand pain (%)16.814.213.5