Common Problems in the Design of Preclinical Animal Experiments

• Activity Number: 157 - Translational Statistics: Problems in Preclinical Studies and a Call for Change
• Type: Topic Contributed
• Date/Time: Tuesday, August 4, 2020 : 10:00 AM to 11:50 AM
• Sponsor: Section on Teaching of Statistics in the Health Sciences
• Author(s): Stanley Lazic*
• Companies: Prioris.ai Inc.
• Keywords: Experimental Design; Pseudoreplication; Preclinical; In vivo; Confounding; Reproducibility

Abstract

Many -- perhaps most -- preclinical animal experiments are poorly designed and executed. Two common problems that severely compromise the results are (1) treatment effects are confounded with biological and technical effects, and (2) the wrong biological entity is treated as the experimental unit, making the sample size artificially inflated (pseudoreplication). We discuss the criteria for determining the appropriate experimental unit and common sources of confounding in animal experiments such as sex, litter, time/order effects, and cages/pens/tanks. No new methods or theory are required to solve these problems, only the standard application of century-old statistical thinking.