Table 1.

Summary of wound rates over time by type of enrichment

Day	Cotton squares	Nylon bone	Mouse house and wheel	Paper rolls	Shredded paper
Before randomization
1	0.25	0.07	0.25	0.08	0.22
7	0.30	0.28	0.29	0.08	0.28
14	0.28	0.18	0.49	0.05	0.17
19	0.42	0.12	0.25	0.07	0.07
After randomization
21	0.63	0.50	0.49	0.57	0.69
23	0.68	0.44	0.42	0.47	0.67
26	0.53	0.30	0.26	0.25	0.40
38	0.27	0.17	0.29	0.05	0.23
41	0.20	0.07	0.23	0.04	0.10
50	0.02	0.04	0.03	0.04	0.09

To visually compare the enrichment groups during the evaluation period, we adjusted for the variation in onset of wound rates. Therefore, wound rates were centralized by subtracting the rate of each group on day 1. After adjustment, the difference in wound rates started at 0 for all groups.