A pain in the back

Erica Weir rightly emphasized the importance of a good clinical assessment (history and physical examination) in her recent review of back pain in children.¹ She went on to list potentially helpful investigations and stated that “Testing for rheumatoid factor . . . may be helpful if a rheumatologic disorder is suspected.” However, a positive result on such a test would be an extremely nonspecific finding in this setting and would be unlikely to add any useful diagnostic information. The role of laboratory investigations in diagnosing rheumatic disease was reviewed recently in CMAJ.²