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.
Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA. Incidence of IBS in a cohort of people with asthma. Dig Dis Sci. 2007 Feb 28;52(2):329-35.
Sorensen HT, Sabroe S, Olsen J, Rothman KJ, Gillman MW, Fisher P. Birth weight as a predictor of young men's intelligence. A historical cohort study. Ugeskr Laeger. 1999 Feb 8;161(6):791-3.