Table 1.

Comparison of Strengths and Weaknesses in Epidemiologic and Experimental Animal Studies

	Strengths	Weaknesses
Epidemiologic Studies	Examination of exposure/effect relationships in species of interest	Increased potential for exposure and outcome misclassification and confounding
	Often able to study effects in heterogeneous population	Limited measures of exposure and dose lead to challenges in characterizing quantitative dose-response relationships
	Better suited to consider true range of population exposures	Can take longer time to observe effects from exposure
	Exposures better reflect temporal nature and delivery mechanism	Relatively more expensive
	Evaluate cumulative exposures and health impacts	Confounding exposures/risk factors
Experimental Animal Studies	Allow for examination of full spectrum of toxic effects	Extrapolations required (interspecies, dose, temporal)
	Facilitates estimation of quantitative dose-response relationships	Dose delivery is artificial and poorly approximates true patterns of exposure
	Reduced misclassification of exposures and outcomes	Homogeneity of experimental animals in genetics, lifestage, diet, and initial health state
	Study times can be shorter and allow for early indication of harm