1. Comparative Effectiveness of Senna to Prevent Problematic Constipation in Pediatric Oncology Patients Receiving Opioids: A Multicenter Study of Clinically Detailed Administrative Data 
Chris Feudtner, MD, PhD, MPH, Jason Freedman, MD, Tammy Kang, MD, MSCE, James W. Womer, BA, Dingwei Dai, PhD, Jennifer Faerber, PhD 
Journal of Pain and Symptom Management 
Volume 48, Issue 2, Pages (August 2014)
DOI: /j.jpainsymman
Copyright © 2014 American Academy of Hospice and Palliative Medicine Terms and Conditions

2. Fig. 1 Comparative effectiveness analysis framework.
Journal of Pain and Symptom Management  , DOI: ( /j.jpainsymman )
Copyright © 2014 American Academy of Hospice and Palliative Medicine Terms and Conditions

3. Fig. 2
Comparison of outcomes in patients exposed and unexposed to senna at baseline.
Journal of Pain and Symptom Management  , DOI: ( /j.jpainsymman )
Copyright © 2014 American Academy of Hospice and Palliative Medicine Terms and Conditions