Somatic Symptoms in Pediatric Patients With Chronic Pain: Proposed Clinical Reference Points for the Children's Somatic Symptoms Inventory (Formerly the Children's Somatization Inventory)

Among youth with chronic pain, elevated somatic symptoms across multiple body systems have been associated with greater emotional distress and functional disability and could represent poor adaptation to pain. The Children's Somatic Symptoms Inventory (formerly the Children's Somatization Inventory) is commonly used to assess somatic symptoms in children. However, no studies have evaluated the clinical usefulness of the measure in the assessment of pediatric patients with chronic pain. This study evaluated the factor structure and clinical relevance of the 24-item Children's Somatic Symptoms Inventory (CSSI-24) in youth (n = 1,150) with mixed chronic pain complaints presenting to a tertiary pain clinic. The CSSI-24 total scores were equal or superior to factor scores as indicators of patients' clinical characteristics (functional disability, pain catastrophizing, fear of pain, and anxiety and depressive symptoms) and parental catastrophizing and protective responses. Tertile-derived clinical reference points for the CSSI-24 total score (18, low; 19-31, moderate; ≥ 32, high) significantly differed on measures of clinical characteristics and parent factors. Controlling for age, sex, pain intensity, and primary pain complaint, the high somatic symptoms group exhibited significantly greater health care use compared with the moderate and low groups. The assessment of somatic symptoms in pediatric patients with chronic pain may provide useful information regarding patients' psychosocial risk and tendency to access health services. Perspective: Clinical reference points based on the CSSI-24 total scores meaningfully differentiated youth with chronic pain on measures of emotional distress, functioning, parent catastrophizing and protective responses, and health care use. Assessing somatic symptoms could provide useful information regarding a pediatric patient's psychosocial risk, tendency to access health services, and need for enhanced care coordination.