Carrigan G, Bradbury BD, Brookhart MA, Capra WB, Chia V, Rothman KJ, Sarsour K, Taylor MD, Brown JS. External comparator groups derived from real-world data used in support of regulatory decision making: use cases and challenges. Curr Epidemiol Rep. 2022 Dec;9:326-37. doi: 10.1007/s40471-022-00305-9
Cole JA, Rothman KJ, Cabral HJ, Zhang Y, Farraye FA. Migraine, fibromyalgia, and depression among people with IBS: a prevalence study. BMC Gastroenterol. 2006 Sep 1;6(26).