Chronic pain is a primary feature of juvenile arthritis (JA) (1). Patients with JA often report mild to moderate pain (2–6). Approximately 25–30% report moderate to severe pain (7, 8), and most children with JA report at least some pain lasting from 30 minutes to 24 hours a day, with a mean of 4.3 hours per day (9). A 2-month daily diary study showed that children with JA report pain on an average of 73% of the days, with the majority (76%) reporting pain on >60% of the days (10). Approximately 60% of children with JA report joint pain at disease onset, 50% report pain at 1-year followup, and 40% continue to report pain 5 years later (11). Moreover, adults who as children were diagnosed with JA report significantly more pain, fatigue, and disability than sex-matched healthy controls (12). Therefore, pain is a significant problem for some children with JA that persists into adulthood and is associated with greater disability. However, the above pain references are from 1997 or earlier, which precedes the use of biologic agents. More recent studies have shown lower levels of pain (13).
In order to effectively document and treat JA-associated pain, we need reliable, valid, and clinically useful measures of pain. Both self-report and observational measures of pain have been used to measure pain in children and adolescents (14, 15). However, observational measures are limited for recurrent or chronic pain, as with JA, because overt pain behaviors tend to habituate or dissipate over time (15). Therefore, self-report measures are preferable when measuring JA-associated pain, except with very young children or children with cognitive deficits. Autonomic measures (e.g., pulse) have been used in JA (16), but are not always considered proxy measures of pain (17). The following is a review of self-report and observational pain measures that have been tested with children and adolescents with JA. For measures that have been used for other pediatric acute and chronic recurring pain conditions, please see the Pediatric Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations (18). All but one of the measures included in the current review are self-report measures.