HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Submit a response Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Related articles in AJPH Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Koopman, J S Articles by Longini, I M Search for Related Content PubMed PubMed Citation Articles by Koopman, J S Articles by Longini, I M, Jr

The ecological effects of individual exposures and nonlinear disease dynamics in populations.

J S Koopman and I M Longini, Jr

Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor 48109.

To describe causally predictive relationships, model parameters and the data used to estimate them must correspond to the social context of causal actions. Causes may act directly upon the individual, during a contact between individuals, or upon a group dynamic. Assuming that outcomes in different individuals are independent puts the causal action directly upon individuals. Analyses making this assumption are thus inappropriate for infectious diseases, for which risk factors alter the outcome of contacts between individuals. Transmission during contact generates nonlinear infection dynamics. These dynamics can so attenuate exposure-infection relationships at the individual level that even risk factors causing the vast majority of infections can be missed by individual-level analyses. On the other hand, these dynamics amplify causal associations between exposure and infection at the ecological level. The amplification and attenuation derive from chains of transmission initiated by exposed individuals but involving unexposed individuals. A study of household exposure to the only vector of dengue in Mexico illustrates the phenomenon. An individual-level analysis demonstrated almost no association between exposure and infection. Ecological analysis, in contrast, demonstrated a strong association. Transmission models that are devoid of any sources of the ecological fallacy are used to illustrate how nonlinear dynamics generate such results.

Related articles in AJPH:

Ecologic analysis as outlook and method.

C Poole
AJPH 1994 84: 715-716. [PDF]  

This article has been cited by other articles:

				J. Ahern, S. Galea, A. Hubbard, L. Midanik, and S. L. Syme "Culture of Drinking" and Individual Problems with Alcohol Use Am. J. Epidemiol., May 1, 2008; 167(9): 1041 - 1049. [Abstract] [Full Text] [PDF]

				E Regidor, J L Gutierrez-Fisac, E Ronda, M E Calle, D Martinez, and V Dominguez Impact of cumulative area-based adverse socioeconomic environment on body mass index and overweight J. Epidemiol. Community Health, March 1, 2008; 62(3): 231 - 238. [Abstract] [Full Text] [PDF]

				S. D. Datta, M. Sternberg, R. E. Johnson, S. Berman, J. R. Papp, G. McQuillan, and H. Weinstock Gonorrhea and Chlamydia in the United States among Persons 14 to 39 Years of Age, 1999 to 2002 Ann Intern Med, July 17, 2007; 147(2): 89 - 96. [Abstract] [Full Text] [PDF]

				J. N.S. Eisenberg, J. C. Scott, and T. Porco Integrating Disease Control Strategies: Balancing Water Sanitation and Hygiene Interventions to Reduce Diarrheal Disease Burden Am J Public Health, May 1, 2007; 97(5): 846 - 852. [Abstract] [Full Text] [PDF]

				J A Cassell and N Low How can chlamydia diagnoses increase when their complications are declining? Sex. Transm. Inf., August 1, 2005; 81(4): 285 - 286. [Full Text] [PDF]

				L. McLaren and P. Hawe Ecological perspectives in health research J. Epidemiol. Community Health, January 1, 2005; 59(1): 6 - 14. [Abstract] [Full Text] [PDF]

				C. A. Holcomb and M.-C. Lin Geographic Variation in the Prevalence of Macular Disease Among Elderly Medicare Beneficiaries in Kansas Am J Public Health, January 1, 2005; 95(1): 75 - 77. [Abstract] [Full Text] [PDF]

				K. E. Poundstone, S. A. Strathdee, and D. D. Celentano The Social Epidemiology of Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome Epidemiol. Rev., July 1, 2004; 26(1): 22 - 35. [Full Text] [PDF]

				J. NEELEMAN The relativity of relative risks: disadvantage or opportunity? The British Journal of Psychiatry, February 1, 2003; 182(2): 101 - 102. [Full Text] [PDF]

				A. Karpati, S. Galea, T. Awerbuch, and R. Levins Variability and Vulnerability at the Ecological Level: Implications for Understanding the Social Determinants of Health Am J Public Health, November 1, 2002; 92(11): 1768 - 1772. [Abstract] [Full Text] [PDF]

				S. Harbarth, S. Cosgrove, and Y. Carmeli Effects of Antibiotics on Nosocomial Epidemiology of Vancomycin-Resistant Enterococci Antimicrob. Agents Chemother., June 1, 2002; 46(6): 1619 - 1628. [Full Text] [PDF]

				S. Greenland Ecologic versus individual-level sources of bias in ecologic estimates of contextual health effects Int. J. Epidemiol., December 1, 2001; 30(6): 1343 - 1350. [Abstract] [Full Text] [PDF]

				S W Wen, K Demissie, D August, and G G Rhoads Level of aggregation for optimal epidemiological analysis: the case of time to surgery and unnecessary removal of the normal appendix J. Epidemiol. Community Health, March 1, 2001; 55(3): 198 - 203. [Abstract] [Full Text] [PDF]

				M. Lipsitch, C. T. Bergstrom, and B. R. Levin From the Cover: The epidemiology of antibiotic resistance in hospitals: Paradoxes and prescriptions PNAS, February 15, 2000; 97(4): 1938 - 1943. [Abstract] [Full Text] [PDF]