Epidemiology, public health, and the rhetoric of false positives.
BACKGROUND
As an observational science, epidemiology is regarded by some researchers as inherently flawed and open to false results. In a recent paper, Boffetta et al. [Boffetta P, McLaughlin JK, LaVecchia C, Tarone RE, Lipworth L, Blot WJ. False-positive results in cancer epidemiology: a plea for epistemological modesty. J Natl Cancer Inst 100:988-995 (2008)] argued that "epidemiology is particularly prone to the generation of false-positive results." They also said "the tendency to emphasize and over-interpret what appear to be new findings is commonplace, perhaps in part because of a belief that the findings provide information that may ultimately improve public health" and that "this tendency to hype new findings increases the likelihood of downplaying inconsistencies within the data or any lack of concordance with other sources of evidence." The authors supported these serious charges against epidemiology and epidemiologists with few examples. Although we acknowledge that false positives do occur, we view the position of Boffetta and colleagues on false positives as unbalanced and potentially harmful to public health.


OBJECTIVE
We aim to provide a more balanced evaluation of epidemiology and its contribution to public health discourse.


CONCLUSIONS
Boffetta and colleagues ignore the fact that false negatives may arise from the very processes that they tout as generating false-positive results. We further disagree with their proposition that false-positive results from a single study will lead to faulty decision making in matters of public health importance. In practice, such public health evaluations are based on all the data available from all relevant disciplines and never to our knowledge on a single study.


CONCLUSIONS
The lack of balance by Boffetta and colleagues in their evaluation of the impact of false-positive findings on epidemiology, the charge that "methodological vigilance is often absent" in epidemiologists' interpretation of their own results, and the false characterization of how epidemiologic findings are used in societal decision making all undermine a major source of information regarding disease risks. We reaffirm the importance of epidemiologic evidence as a critical component of the foundation of public health protection.
Blair
Aaron
A
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA. blaira@mail.nih.gov
Saracci
Rodolfo
R
Vineis
Paolo
P
Cocco
Pierluigi
P
Forastiere
Francesco
F
Grandjean
Philippe
P
Kogevinas
Manolis
M
Kriebel
David
D
McMichael
Anthony
A
Pearce
Neil
N
Porta
Miquel
M
Samet
Jonathan
J
Sandler
Dale P
DP
Costantini
Adele Seniori
AS
Vainio
Harri
H
D015982:Bias; D001943:Breast Neoplasms / Q000139:chemically induced; D003069:Coffee / Q000009:adverse effects; D003632:Dichlorodiphenyldichloroethane / Q000633:toxicity; D004812:Epidemiologic Methods; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D010190:Pancreatic Neoplasms / Q000209:etiology; D011634:Public Health
D003069:Coffee; D003632:Dichlorodiphenyldichloroethane