Table 4.

Urinary arsenic ($\mathrm{\mu }\mathrm{g}/\mathrm{g}$ creatinine) and arsenic metabolites (percentage species) at the final follow-up visit comparing Intensive arm to mHealth and Filter only arm participants in the Strong Heart Water Study randomized controlled trial ($N=74$).

Arsenic levels and metabolite	mHealth and Filter arm ($N=46$)	Intensive arm ($N=28$)	Intensive arm vs. mHealth and Filter arm ($N=74$)a			mHealth and Filter arm ($N=46$)	Intensive arm ($N=28$)	Intensive arm vs. mHealth and Filter arm ($N=74$)a
	GM (range)	GM (range)	GM ratio	(95% CI)	$p$-Value	Mean (range)	Mean (range)	MD	(95% CI)	$p$-Value
Urinary arsenic ($\mathrm{\mu }\mathrm{g}/\mathrm{g}$ creatinine)	6.55 (1.51–46.7)	7.82 (1.45–32.7)	1.21	(0.77, 1.90)	0.413	—	—	—	—	—
Arsenic metabolites
iAs%	—	—	—	—	—	11.8 (3.68–30.6)	18.8 (1.40–80.3)	4.89	($-1.30$, 11.08)	0.122
MMA%	—	—	—	—	—	11.8 (3.26–23.1)	11.6 (3.29–18.9)	$-1.09$	($-2.57$, 0.38)	0.145
DMA%	—	—	—	—	—	76.3 (53.5–93.1)	69.7 (16.5–90.3)	$-3.80$	($-9.99$, 2.40)	0.230

Note: Urinary arsenic was defined as the sum of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) measurements, with GMs reported. —, Not applicable; CI, confidence interval; DMA%, percentage dimethylated arsenic; GM, geometric mean; iAs%, percentage inorganic arsenic species; MD, mean difference; %, percentages of species over the sum of inorganic and methylated arsenic species; MMA%, percentage of monomethylated arsenic.

^a Adjusted for sociodemographic factors (sex and age) and lifestyle factors (ever smoking and baseline BMI). Urinary arsenic was log-transformed for analysis. Regression analyses were performed using generalized estimating equations to account for clustering at the household level using an exchangeable correlation. Participants without urinary arsenic data were excluded.