see also:

• the swollen joint and its diagnostic workup
• rheumatoid arthritis
• arthritis - clinical patterns

• rh factor is a blood test often used in assessment of patients with arthritis
• this test is NOT useful for screening:
  • it is nonspecific and insensitive - the presence of rheumatoid factor does not indicate rheumatoid arthritis, nor does its absence rule out rheumatoid arthritis
  • thus, a positive rheumatoid factor in a patient with nonspecific symptoms may precipitate unnecessary investigations