American Journal of Epidemiology Advance Access published online on April 12, 2007
American Journal of Epidemiology, doi:10.1093/aje/kwm092
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Invited Commentary: When Bad Genes Look Good—APOE*E4, Cognitive Decline, and Diagnostic Thresholds
1 Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY
2 Department of Society, Human Development, and Health, Harvard School of Public Health, Boston, MA
Correspondence to Dr. M. Maria Glymour, 722 West 168th Street, Room 1603, New York, NY 10032 (e-mail: mg2630{at}columbia.edu).
Received for publication November 30, 2006. Accepted for publication December 5, 2006.
Scientific interest frequently focuses on how factors that influence disease onset subsequently affect disease progression. In this commentary, the author discusses four sources of bias that arise in such work. The focus is on Tyas et al.'s analyses (Am J Epidemiol 2007;165:000–00) of how the apolipoprotein E *E4 allele, a well-documented risk factor for Alzheimer's disease, influences progression of cognitive impairments from mild or global cognitive impairment to dementia or death. The author addresses four phenomena that can lead to spurious (noncausal) associations between apolipoprotein E *E4 status and rate of progression of cognitive impairments: beginning observations in the middle of a developing pathologic process, survivor bias, uncertainty in the timing of disease diagnosis, and nonlinear disease progression trajectories. Because these sources of bias are potentially relevant in any study of how risk factors for disease onset influence disease progression, the author advocates assessing their likely magnitude in specific contexts when interpreting results.
apolipoproteins E; bias (epidemiology); cognition disorders; cohort studies; dementia; disease progression
Abbreviations: APOE, apolipoprotein E; MCI, mild cognitive impairment; QP, quickly progressing; SP, slowly progressing
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  D. B. Petitti, V. C. Crooks, V. Chiu, J. G. Buckwalter, and H. C. Chui Incidence of Dementia in Long-term Hormone Users Am. J. Epidemiol., March 15, 2008; 167(6): 692 - 700. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Tyas, J. C. Salazar, D. A. Snowdon, M. F. Desrosiers, K. P. Riley, M. S. Mendiondo, and R. J. Kryscio Tyas et al. Respond to "Predictors of Rate of Change in Disease Progression" Am. J. Epidemiol., June 1, 2007; 165(11): 1247 - 1247. [Full Text] [PDF]
|
|