Other variables will also be collected as part of both aims, including pain as assessed by a standardized pain scale, physician assessment of global disease activity, and functional status as determined by the childhood health assessment questionnaire (CHAQ), a validated, reliable measure of functional status in JIA. These last assessments are 3 of the 6 measures of the ACR Pediatric 30, a validated measure used in clinical trials in JIA (Giannini et al., 1997). Other patient data that will be collected include JIA subtype, duration of disease, age of onset, age at procedure, race/ethnicity, concurrent medications, and whether the procedure required the use of general anesthesia.