Table 8.

Statistical analyses used in guideline developmental neurotoxicity studies.

	Acetamiprid – WIL Laboratories	Imidacloprid – Bayer Laboratory	Thiacloprid, Clothianidin & Dinotefuran – Charles River (formerly Argus) Laboratories	Thiamethoxam – Syngenta Central Toxicology Laboratory
Body weight	One-way (dose, interval) ANOVA followed by Dunnett’s	Bartlett’s test for equal variance (α=0.001)One-way ANOVA and Dunnett’s (equal variance)Kruskal–Wallis and Mann–Whitney (unequal variance) tests	Bartlett’s test for equal variance (α=0.05)ANOVA followed by Dunnett’s (equal variance)Kruskal–Wallis (unequal variance) followed by Dunn’s (≤75% scores tied) or Fisher’s exact (>75% scores tied)	One-way ANOVA and ANCOVA (with initial body weight as covariate), followed by Student’s t-test
Variables with graded or count scores	Not applicable	Not applicable	Kruskal–Wallis and Dunn’s (≤75% scores tied) or Fisher’s exact (>75%scores tied)	For proportions of males or females affected, Fisher’s exact test.
Motor activity	One-way (dose, interval) ANOVA for total and intersession for each sex followed by Dunnett’s; three-way (dose, interval, sex) RANOVA (Proc Mix SAS using AR(1) or CS models). If dose × sex interaction is significant then males and females are analyzed separately. If dose ×interval interaction is significant, then ANOVA for each interval followed by Dunnett’s. If dose × interval interaction is not significant and dose effect is significant then Dunnett’s test is conducted on the pooled cumulative session data	Two-way RANOVA (dose, interval) and Dunnett’s tests	Two-way RANOVA (dose, interval). If dose × interval interaction was significant, then ANOVA for each interval followed by Dunnett’s. If interaction was not significant but there was a significant dose effect then Dunnett’s was conducted on data pooled across intervals	One-way ANOVA followed by Student’s t-test. Conducted for each time interval and overall
Acoustic Startle	Same as motor activity except factors included dose, trial and sex	Two-way RANOVA (dose, interval) and Dunnett’s tests	Same as motor activity except the factors included trial instead of interval	One-way ANOVA followed by Student’s t-test, for maximum amplitude and time to maximum amplitude
Biel Maze	Same as motor activity except factors included dose, trial and sex and each path was analyzed separately	Not applicable	Not applicable	Not applicable
M-Maze or Y-Maze	Not applicable	ANOVA and Dunnett’s tests	Same as for body weight	ANOVA following double arcsine transformation of Freeman and Tukey’s, then Student’s t-test
Passive avoidance (latency, trials-to- criterion)	Not applicable	Kruskal–Wallis, Wilcoxon and Fisher’s exact tests	Same as for body weight	Not applicable
Neuropathology	Kolmogorov–Smirnov test	Chi-square and Fisher’s exact tests	Fisher’s exact (one-tailed) test	Fisher’s exact test
Brain morphometry	ANOVA followed by Dunnett’s	ANOVA or T-test (two groups)	ANOVA (continuous data)	ANOVA and ANCOVA using final body weight as covariate