American Journal of Epidemiology Advance Access originally published online on April 19, 2006
American Journal of Epidemiology 2006 163(12):1149-1156; doi:10.1093/aje/kwj149
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Practice of Epidemiology |
Variable Selection for Propensity Score Models
1 Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
2 Departments of Epidemiology and Medicine, Boston University Medical Center, Boston, MA
3 Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
Correspondence to Dr. M. Alan Brookhart, Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital and Harvard Medical School, 1620 Tremont Street, Suite 3030, Boston, MA 02120 (e-mail: abrookhart{at}rics.bwh.harvard.edu).
Despite the growing popularity of propensity score (PS) methods in epidemiology, relatively little has been written in the epidemiologic literature about the problem of variable selection for PS models. The authors present the results of two simulation studies designed to help epidemiologists gain insight into the variable selection problem in a PS analysis. The simulation studies illustrate how the choice of variables that are included in a PS model can affect the bias, variance, and mean squared error of an estimated exposure effect. The results suggest that variables that are unrelated to the exposure but related to the outcome should always be included in a PS model. The inclusion of these variables will decrease the variance of an estimated exposure effect without increasing bias. In contrast, including variables that are related to the exposure but not to the outcome will increase the variance of the estimated exposure effect without decreasing bias. In very small studies, the inclusion of variables that are strongly related to the exposure but only weakly related to the outcome can be detrimental to an estimate in a mean squared error sense. The addition of these variables removes only a small amount of bias but can increase the variance of the estimated exposure effect. These simulation studies and other analytical results suggest that standard model-building tools designed to create good predictive models of the exposure will not always lead to optimal PS models, particularly in small studies.
confounding factors (epidemiology); effect modifiers (epidemiology); models, statistical; propensity score; regression analysis; simulation; subset selection; variable selection
Abbreviations: MSE, mean squared error; PS, propensity score
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
C. O. Weiss, H. H. Hoenig, R. Varadhan, E. M. Simonsick, and L. P. Fried Relationships of Cardiac, Pulmonary, and Muscle Reserves and Frailty to Exercise Capacity in Older Women J Gerontol A Biol Sci Med Sci, October 12, 2009; (2009) glp147v1. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. M. Foster, E. Wiley-Exley, and L. Bickman Old Wine in New Skins: The Sensitivity of Established Findings to New Methods Eval Rev, June 1, 2009; 33(3): 281 - 306. [Abstract] [PDF] |
||||
![]() |
S. S. Gill, G. M. Anderson, H. D. Fischer, C. M. Bell, P. Li, S.-L. T. Normand, and P. A. Rochon Syncope and Its Consequences in Patients With Dementia Receiving Cholinesterase Inhibitors: A Population-Based Cohort Study Arch Intern Med, May 11, 2009; 169(9): 867 - 873. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. J. Meador, G. A. Baker, N. Browning, J. Clayton-Smith, D. T. Combs-Cantrell, M. Cohen, L. A. Kalayjian, A. Kanner, J. D. Liporace, P. B. Pennell, et al. Cognitive Function at 3 Years of Age after Fetal Exposure to Antiepileptic Drugs N. Engl. J. Med., April 16, 2009; 360(16): 1597 - 1605. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Dore, K. L. Lapane, A. N. Trivedi, V. Mor, and M. A. Weinstock Association Between Statin Use and Risk for Keratinocyte Carcinoma in the Veterans Affairs Topical Tretinoin Chemoprevention Trial Ann Intern Med, January 6, 2009; 150(1): 9 - 18. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. P. McDonald, M. R. Marshall, D. W. Johnson, and K. R. Polkinghorne Relationship between Dialysis Modality and Mortality J. Am. Soc. Nephrol., January 1, 2009; 20(1): 155 - 163. [Abstract] [Full Text] [PDF] |
||||
![]() |
M Blagojevic, C Jinks, and K P Jordan The influence of consulting primary care on knee pain in older people: a prospective cohort study Ann Rheum Dis, December 1, 2008; 67(12): 1702 - 1709. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Cummings Propensity Scores Arch Pediatr Adolesc Med, August 1, 2008; 162(8): 734 - 737. [Full Text] [PDF] |
||||
![]() |
S. Kudoh, H. Kato, Y. Nishiwaki, M. Fukuoka, K. Nakata, Y. Ichinose, M. Tsuboi, S. Yokota, K. Nakagawa, M. Suga, et al. Interstitial Lung Disease in Japanese Patients with Lung Cancer: A Cohort and Nested Case-Control Study Am. J. Respir. Crit. Care Med., June 15, 2008; 177(12): 1348 - 1357. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. Cadarette, J. N. Katz, M. A. Brookhart, T. Sturmer, M. R. Stedman, and D. H. Solomon Relative Effectiveness of Osteoporosis Drugs for Preventing Nonvertebral Fracture Ann Intern Med, May 6, 2008; 148(9): 637 - 646. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Schmoor, A. Caputo, and M. Schumacher Evidence from Nonrandomized Studies: A Case Study on the Estimation of Causal Effects Am. J. Epidemiol., May 1, 2008; 167(9): 1120 - 1129. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Greenland Invited Commentary: Variable Selection versus Shrinkage in the Control of Multiple Confounders Am. J. Epidemiol., March 1, 2008; 167(5): 523 - 529. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Schootman, E. M. Andresen, F. D. Wolinsky, T. K. Malmstrom, J. P. Miller, Y. Yan, and D. K. Miller The Effect of Adverse Housing and Neighborhood Conditions on the Development of Diabetes Mellitus among Middle-aged African Americans Am. J. Epidemiol., August 15, 2007; 166(4): 379 - 387. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Shrier, R. W. Platt, and R. J. Steele RE: "VARIABLE SELECTION FOR PROPENSITY SCORE MODELS" Am. J. Epidemiol., July 15, 2007; 166(2): 238 - 239. [Full Text] [PDF] |
||||
![]() |
S. S. Gill, S. E. Bronskill, S.-L. T. Normand, G. M. Anderson, K. Sykora, K. Lam, C. M. Bell, P. E. Lee, H. D. Fischer, N. Herrmann, et al. Antipsychotic Drug Use and Mortality in Older Adults with Dementia Ann Intern Med, June 5, 2007; 146(11): 775 - 786. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Sturmer, S. Schneeweiss, K. J. Rothman, J. Avorn, and R. J. Glynn Performance of Propensity Score Calibration--A Simulation Study Am. J. Epidemiol., May 15, 2007; 165(10): 1110 - 1118. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Greenland Bayesian perspectives for epidemiological research. II. Regression analysis Int. J. Epidemiol., February 28, 2007; (2007) dyl289v1. [Abstract] [Full Text] [PDF] |
||||










