Table 11. Number of animals reported in methods and results sections for each study.

Species	Methods section	Results section
		0–9	10–19	20–29	30–39	40+	??†
Mouse (n = 72)	0–9	2	1	1	0	0	0
	10–19	0	3	0	1	0	2
	20–29	0	0	4	0	0	3
	30–39	0	0	0	2	0	2
	40+	0	0	0	0	7	5
	??	4	8	2	5	15	5
Primate (n = 86)	0–9	37	0	0	0	0	9
	10–19	0	12	0	0	0	6
	20–29	0	0	4	0	0	4
	30–39	0	0	0	4	0	0
	40+	0	0	0	0	4	0
	??	6	0	0	0	0	0
Rat (n = 113)	0–9	3	0	0	0	1	4
	10–19	0	13	0	1	0	6
	20–29	0	1	14	0	0	3
	30–39	0	0	1	5	0	5
	40+	0	2	0	3	15	8
	??	2	5	5	3	7	6
All (n = 271)	0–9	40	1	1	0	0	13
	40+	0	2	0	3	26	13
	??	12	13	7	8	22	11

^†The ‘??’ symbol indicates that the number of animals was not clear or not reported. In 35% (69/198) of the papers which did report animal numbers, the numbers differed between the methods and the results sections of the paper.