Table 2.
Multivariable regression analysis of diversity indexes
| Diversity index | Factors | Multivariable regression | Factors | Multivariable regression [paired analysis of treatments] | ||
|---|---|---|---|---|---|---|
| Coefficient | p-value | Coefficient | p-value | |||
| Shannon | Sex [male vs female] | 0.16 | 0.43 | Sex [male vs female] | 0.25 | 0.43 |
| Age [per year increase] | −0.01 | 0.22 | Age [per year increase] | −0.003 | 0.81 | |
| Treatment | <0.0001 | Time since diagnosis [per year increase] | −0.02 | 0.51 | ||
| Anti-TNF vs non-IBD control | −1.56 | <0.0001 | State [remission vs active] | −0.16 | 0.59 | |
| Corticoid vs non-IBD control | −0.92 | <0.0001 | Treatment [anti-TNF vs corticoid] | −0.59 | 0.06 | |
| Simpson | Sex [male vs female] | 0.03 | 0.18 | Sex [male vs female] | 0.05 | 0.18 |
| Age [per year increase] | 0.0001 | 0.38 | Age [per year increase] | −0.002 | 0.38 | |
| Treatment | 0.0003 | Time since diagnosis [per year increase] | 0.001 | 0.71 | ||
| Anti-TNF vs non-IBD control | −0.09 | <0.0001 | State [remission vs active] | −0.02 | 0.53 | |
| Corticoid vs non-IBD control | −0.04 | 0.13 | Treatment [anti-TNF vs corticoid] | −0.06 | 0.10 | |
| Chao1 | Sex [male vs female] | 56.04 | 0.59 | Sex [male vs female] | −81.34 | 0.47 |
| Age [per year increase] | −6.49 | 0.15 | Age [per year increase] | 1.21 | 0.82 | |
| Treatment | <0.0001 | Time since diagnosis [per year increase] | −17.19 | 0.05 | ||
| Anti-TNF vs non-IBD control | −768.25 | <0.0001 | State [remission vs active] | −59.97 | 0.56 | |
| Corticoid vs non-IBD control | −482.16 | <0.0001 | Treatment [anti-TNF vs corticoid] | −233.35 | 0.03 | |
| Phylogenetic diversity | Sex [male vs female] | 2.32 | 0.45 | Sex [male vs female] | −1.73 | 0.55 |
| Age [per year increase] | −0.12 | 0.35 | Age [per year increase] | 0.08 | 0.57 | |
| Treatment | <0.0001 | Time since diagnosis [per year increase] | −0.19 | 0.38 | ||
| Anti-TNF vs non-IBD control | −25.49 | <0.0001 | State [remission vs active] | −1.14 | 0.67 | |
| Corticoid vs non-IBD control | −18.06 | <0.0001 | Treatment [anti-TNF vs corticoid] | −6.07 | 0.03 | |
IBD, inflammatory bowel disease; TNF, tumour necrosis factor. Multivariable linear regressions were performed to address the effect of treatment regimen on each diversity index, adjusting for confounders that include sex, age, time since diagnosis [years] and disease state [active vs. remission]. A p-value less than 0.05 was considered statistically significant.