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Table 5 The Longitudinal analyses of methemoglobin and predictor variables (n = 327)

From: Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

Parameter

β estimate

SE

95% CI

p-value

Intercept

-0.841

0.595

-2.007, 0.324

0.157

Gestational age (weeks)

-0.043

0.005

-0.054, -0.033

<0.0001

Carboxyhemoglobin

0.121

0.043

0.037, 0.205

0.005

Vegetable 24 hrs (yes)

-0.165

0.127

-0.414, 0.084

0.194

Cured meats (yes)

0.009

0.104

-0.196, 0.213

0.934

Water intake (cups/day)

-0.011

0.013

-0.037, 0.015

0.409

Drinking water (bottled)

-0.211

0.157

-0.519, 0.098

0.181

Water source (private well)

-0.099

0.134

-0.362, 0.162

0.455

Season methemoglobin tested (fall vs. winter)

0.388

0.143

0.107, 0.668

0.007

Season methemoglobin tested (spring vs. winter)

-0.146

0.153

-0.445, 0.154

0.340

Season methemoglobin tested (summer vs. winter)

0.039

0.154

-0.262, 0.342

0.796

Water treatment (none vs. nitrate removal)

0.029

0.205

-0.372, 0.430

0.887

Water treatment (other vs. nitrate removal)

0.321

0.185

-0.042, 0.684

0.082

Vitamin use (no)

-0.140

0.163

-0.459, 0.177

0.387

Nitrosatable drugs (no)

0.149

0.125

-0.096, 0.394

0.234