Evaluating Bilateral Phenomena: The Case of Pain in Sickle Cell Disease (SCD)

• Activity Number: 360
• Type: Contributed
• Date/Time: Tuesday, August 3, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Biometrics Section
• Author(s): Bassam A. Dahman and Donna K. McClish*+
• Companies: Virginia Commonwealth University
• Keywords: Bilateralism ; symmetry ; bilateral ; sickle cell disease

Abstract

Bilateralism in biological systems is the conditional co-occurrence of an event on both sides of a symmetric system given that the event occurred at least on one side. A methodology for testing this phenomenon is presented. Two measures were developed to evaluate the presence of bilateralism beyond chance. Nonparametric confidence intervals were constructed using the bootstrap percentile method. These nonparametric confidence intervals were used in testing the null hypothesis of no bilateralism. The properties of these measures in testing for bilateralism are presented using a simulation study. Both measures had similar properties that are affected by difference between the prevalence on both sides. The application of this method to evaluate if pain is bilateral in SCD is presented. The results show higher % of bilateral pain among SCD than expected.