AIM: To evaluate the reliability of an instrument that measures disability arising from episodic abdominal pain in patients with suspected sphincter of Oddi dysfunction (SOD).
METHODS: Although several treatments have been utilized to reduce pain and associated disability, measurement tools have not been developed to reliably track outcomes. Two pilot studies were conducted to assess test-retest reliability of a newly developed instrument, the recurrent abdominal pain intensity and disability (RAPID) instrument. The RAPID score is a 90-d summation of days where productivity for various daily activities is reduced as a result of abdominal pain episodes, and is modeled after the migraine disability assessment instrument used to measure headache-related disability. RAPID was administered by telephone on 2 consecutive occasions in 2 consenting populations with suspected SOD: a pre-sphincterotomy population (Pilot I, n = 55) and a post-sphincterotomy population (Pilot II, n = 70).
RESULTS: The average RAPID scores for Pilots I and II were: 82 d (median: 81.5 d, SD: 64 d) and 48 d (median: 0 d, SD: 91 d), respectively. The concordance between the 2 assessments for both populations was very good: 0.81 for the pre-sphincterotomy population and 0.95 for the post-sphincterotomy population.
CONCLUSION: The described pilot studies suggest that RAPID is a reliable instrument for measuring disability resulting from abdominal pain in suspected SOD patients.
Keywords: Sphincter of Oddi, Abdominal pain, Disability measurement, Reproducibility of results, Pain measurement, Episodic pain