TABLE 2.

Community diversity by group as measured by Shannon, Chao, dominance, and evenness metrics^a

Group	Shannon index	Chao index	Dominance index	Evenness index
Iatrogenic stenosis	2.46 ± 1.11	72.2 ± 98.6	0.23 ± 0.27	0.32 ± 0.13
Idiopathic stenosis	2.6 ± 0.65	51.08 ± 15.29	0.18 ± 0.12	0.35 ± 0.16
Internal control	2.7 ± 0.85	123.76 ± 159.35	0.18 ± 0.13	0.24 ± 0.07
External control	2.50 ± 0.35	97.15 ± 81.41	0.17 ± 0.06	0.27 ± 0.10

^aMean value ± standard deviation was obtained for each index relative to group. No statistical differences were noted by group, where internal controls represented disease-free regions from patients with stenosis and external controls represented disease-free regions from patients without stenosis.