Subgroups of Pediatric Patients with Functional Abdominal Pain: Replication, Parental Characteristics, and Health Service Use.

OBJECTIVES Prior work in a cohort of youth with functional abdominal pain (FAP) identified patient subgroups (High Pain Dysfunctional, High Pain Adaptive, Low Pain Adaptive) that predicted differences in the course of FAP from childhood into young adulthood. We aimed to replicate these subgroups in a new sample of adolescents with FAP using the original classification algorithm and to extend subgroup characteristics to include parental characteristics and health service use. METHODS Adolescents (n=278; ages 11-17▒y, 66% females) presenting to a gastroenterology clinic for abdominal pain and their parents (92% mothers) completed self-report measures; adolescents also completed a 7-day pain diary. RESULTS The replicated patient subgroups exhibited distress and impairment similar to subgroups in the original sample. Moreover, in novel findings, the High Pain Dysfunctional subgroup differed from other subgroups by the predominance of mother-daughter dyads jointly characterized by high levels of anxiety, depressive symptoms, pain behavior, and pain catastrophizing. The High Pain Dysfunctional subgroup used more health care services than Low Pain Adaptive but did not differ from High Pain Adaptive. DISCUSSION Findings replicate and extend the original FAP classification and suggest that the subgroups have unique patient and parent features that may reflect distinct illness mechanisms requiring different treatments.