Table 4.

Linear regression results of the effect of treatment group on the change in biodiversity

Outcome	Linear regression			Adjusted P value*
	Predictor	Estimate (SE)	Unadjusted P value
Shannon diversity index change (week 8—baseline)
Oral wash (N=40)	Treatment group†	−0.349 (0.091)	0.0005	0.0010
	Baseline index	−0.197 (0.073)	0.0100
Sputum (N=35)	Treatment group	−0.622 (0.169)	0.0008	0.0010
	Baseline index	−0.312 (0.111)	0.0083
Simpson diversity index change (week 8—baseline)
Oral wash (N=40)	Treatment group	−0.030 (0.008)	0.0005	0.0010
	Baseline index	−0.196 (0.114)	0.0938
Sputum (N=35)	Treatment group	−0.091 (0.034)	0.0123	0.0123
	Baseline index	−0.109 (0.179)	0.5472

*A step-down Bonferroni p value adjustment is made for the two comparisons (oral wash and sputum) within each diversity index.

†Treatment group is coded as chlorhexidine=1, placebo=0.