Candrilli SD, Davis KL, Iyer S. Impact of constipation on opioid use patterns, health care resource utilization, and costs in cancer patients on opioid therapy. J Pain Palliat Care Pharmacother. 2009 Sep 1;23(3):231-41.
Estrada CA, Unterborn JN, Price J, Thompson D, Gibson L. Judging the effectiveness of clinical pathways for pneumonia: the role of risk adjustment. Eff Clin Pract. 2000 Sep 1;3(5):221-8.