title: Structural estimates of treatment effects on outcomes using retrospective data: an application to ductal carcinoma in situ.
abstract: Analysis of observational cohort data is subject to bias from unobservable risk selection. The authors compared econometric models and treatment effectiveness estimates using the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare claims data for women diagnosed with ductal carcinoma in situ. Treatment effectiveness estimates for mastectomy and breast-conserving surgery (BCS) with or without radiotherapy were compared using three different models: simultaneous-equations model, discrete-time survival model with unobserved heterogeneity (frailty), and proportional hazards model. Overall trends in disease-free survival (DFS), or time to first subsequent breast event, by treatment are similar regardless of the model, with mastectomy yielding the highest DFS over 8 years of follow-up, followed by BCS with radiotherapy, and then BCS alone. Absolute rates and direction of bias varied substantially by treatment strategy. DFS was underestimated by single-equation and frailty models compared with the simultaneous-equations model and randomized controlled trial results for BCS with radiotherapy and overestimated for BCS alone.
authors: Department of Medicine, Division of General Internal Medicine, New York University School of Medicine and Cancer Institute, USA. heather.gold@nyumc.org
authors: Heather Taffet
authors: HT
authors: Gold
authors: Melony E S
authors: ME
authors: Sorbero
authors: Jennifer J
authors: JJ
authors: Griggs
authors: Huong T
authors: HT
authors: Do
authors: Andrew W
authors: AW
authors: Dick
references: Cancer. 2008 Dec 1;113(11):3108-15
references: 18932243
references: J Clin Oncol. 1996 Mar;14(3):754-63
references: 8622021
references: Lancet. 2000 Feb 26;355(9205):724-5
references: 10703809
references: Lancet. 1999 Jun 12;353(9169):1993-2000
references: 10376613
references: J Natl Cancer Inst. 2009 Oct 7;101(19):1337-47
references: 19720966
references: J Health Soc Behav. 1995 Mar;36(1):1-10
references: 7738325
references: Int J Radiat Oncol Biol Phys. 2006 Aug 1;65(5):1353-60
references: 16765531
references: JAMA. 1996 Mar 27;275(12):913-8
references: 8598618
references: J Clin Epidemiol. 2000 Dec;53(12):1258-67
references: 11146273
references: J Natl Cancer Inst. 2002 Oct 16;94(20):1546-54
references: 12381707
references: Lancet. 2000 Feb 12;355(9203):528-33
references: 10683002
references: Med Care. 2004 Mar;42(3):267-75
references: 15076826
references: Ann Intern Med. 1997 Dec 1;127(11):1013-22
references: 9412283
references: Stat Med. 2006 Feb 15;25(3):389-413
references: 16382420
references: Health Econ. 2003 Mar;12(3):171-86
references: 12605463
references: Med Care. 2009 Sep;47(9):986-92
references: 19648837
references: Surg Oncol. 2003 Dec;12(4):221-40
references: 14998563
references: J Clin Oncol. 2008 Mar 10;26(8):1247-52
references: 18250350
references: J Clin Epidemiol. 1997 Aug;50(8):939-45
references: 9291879
references: N Engl J Med. 1993 Jun 3;328(22):1581-6
references: 8292119
references: Oncology (Williston Park). 1997 Mar;11(3):393-406, 409-10; discussion 413-5
references: 9109132
references: Eur J Cancer. 2001 Dec;37(18):2365-72
references: 11720829
references: J Natl Cancer Inst. 2006 Sep 20;98(18):1302-10
references: 16985249
references: Semin Oncol. 2001 Aug;28(4):400-18
references: 11498833
references: J Natl Cancer Inst. 2004 Mar 17;96(6):443-8
references: 15026469
references: J Natl Cancer Inst. 2001 Sep 5;93(17):1344-6
references: 11535710
references: J Clin Oncol. 1998 Aug;16(8):2625-31
references: 9704712
references: Cancer. 2005 Nov 1;104(9):1840-8
references: 16136599
references: Arch Intern Med. 2000 Apr 10;160(7):953-8
references: 10761960
references: J Clin Oncol. 2006 Mar 1;24(7):1031-6
references: 16461781
references: J Natl Cancer Inst. 2011 Jan 19;103(2):92-104
references: 21200025
references: J Clin Oncol. 2006 Jul 20;24(21):3381-7
references: 16801628
references: Health Care Financ Rev. 1996 Fall;18(1):237-46
references: 10165033
references: Lancet. 1995 May 6;345(8958):1154-7
references: 7723550
references: Biometrics. 1978 Mar;34(1):57-67
references: 630037
references: Cancer Epidemiol Biomarkers Prev. 1998 Aug;7(8):689-96
references: 9718221