The American College of Rheumatology (ACR) published criteria for the diagnosis of osteoarthritis involving the hand based on clinical findings.
Ten selected joints evaluated for hard tissue enlargement and deformity:
(1) second distal interphalangeal (DIP) joint, left hand
(2) third distal interphalangeal (DIP) joint, left hand
(3) second distal interphalangeal (DIP) joint, right hand
(4) third distal interphalangeal (DIP) joint, right hand
(5) second proximal interphalangeal (PIP) joint, left hand
(6) third proximal interphalangeal (PIP) joint, left hand
(7) second proximal interphalangeal (PIP) joint, right hand
(8) third proximal interphalangeal (PIP) joint, right hand
(9) first carpometacarpal (CMC) joint, left hand
(10) first carpometacarpal (CMC) joint, right hand
Traditional format:
(1) hand pain, aching or stiffness, AND
(2) 3 or 4 of the following:
(2a) hard tissue enlargement in >= 2 of the 10 selected joints
(2b) deformity of >= 1 of the 10 selected joints
(2c) hard tissue enlargement of >= 2 DIP joints (out of 8, with inclusion of DIP of digits 4 and 5 on the left and right hands)
(2d) swelling of 0 – 2 (< 3) metacarpophalangeal (MCP) joints
Classification tree format: all of the following:
(1) hand pain, aching or stiffness
(2) hard tissue enlargement in >= 2 of the 10 selected joints
(3) swelling of 0 – 2 (< 3) MCP joints
(4) one or both of the following
(4a) hard tissue enlargement of >= 2 DIP joints (out of 8, with inclusion of DIP of digits 4 and 5 on the left and right hands)
(4b) deformity in >= 1 of the 10 selected joints
NOTE: In Table 6 (page 1607), the last item is "deformity of 2 or more of the 10 selected joints." However, in Figure 1 page 1606, which is graphical representation of the table, >= 1 is used. This matches the traditional format.
Performance characteristics:
• traditional format has a sensitivity of 94% and specificity of 87%
• classification tree format has a sensitivity of 92% and specificity of 98%
