Classification Tree for Diagnosis of Rheumatoid Arthritis

Criteria

Finding

Duration

arthritis of 3 or more joints

at least 3 joints areas simultaneously have soft tissue swelling or fluid observed by a physician; 14 possible areas include left and right PIP. MCP, wrist, elbow, knee, ankle and MTP joints.

>= 6 weeks

arthritis of wrist

arthritis of MCP

arthritis of MCP or wrist

arthritis of MCP and wrist

soft tissue swelling or fluid of specified area observed by physician; if both MCP and wrist are specified, involvement must be simultaneous

>= 6 weeks

symmetrical swelling

simultaneous involvement of the same joint areas on both sides of the body

>= 6 weeks

serum rheumatoid factor

increased rheumatoid factor

radiographic changes

characteristic changes on posterioranterior hand and wrist radiographs, with erosions or unequivocal bony decalcifications localized in or most marked adjacent to the involved joints; osteoarthritis changes alone do not qualify

Diagnosis

Criteria Present

RA (decision tree point 1)

(a) arthritis present in 3 or more joints

(b) X-ray changes present; if no X-ray data available, then MCP swollen

RA (decision tree point 2)

(a) arthritis present in 3 or more joints

(b) X-ray changes not present, or if X-ray not available then no swelling of MCP

(c) rheumatoid factor present; if rheumatoid factor data not available, then wrist swollen

no RA (decision tree point 3)

(a) arthritis present in 3 or more joints

(b) X-ray changes not present, or if X-ray not available then no swelling of MCP

(c) rheumatoid factor not present, or if rheumatoid factor not available, then no swelling of wrist

(d) swelling of both MCP and wrist not present

RA (decision tree point 4)

(a) arthritis present in 3 or more joints

(b) X-ray changes not present, or if X-ray not available then no swelling of MCP

(c) rheumatoid factor not present, or if rheumatoid factor not available, then no swelling of wrist

(d) swelling of both MCP and wrist present

RA (decision tree point 5)

(a) arthritis not present in 3 or more joints

(b) rheumatoid factor present, or if rheumatoid factor not available, then wrist swollen

(c) swelling of joints symmetrical

RA (decision tree point 6)

(a) arthritis not present in 3 or more joints

(b) rheumatoid factor present, or if rheumatoid factor not available, then wrist swollen

(c) swelling of joints not symmetrical

(d) either MCP or wrists swollen

no RA (decision tree point 7)

(a) arthritis not present in 3 or more joints

(b) rheumatoid factor present, or if rheumatoid factor not available, then wrist swollen

(c) swelling of joints not symmetrical

(d) both MCP and wrists not swollen

no RA (decision tree point 8)

(a) arthritis not present in 3 or more joints

(b) rheumatoid factor not present; if rheumatoid factor data not available, then wrists not swollen