Table 3.

The weighted linear regression for the time-related change in blood lead level in pregnant females.

	Crude model			Adjusted model
	β coefficient	95% CI	P	β coefficient	95% CI	P
Year	−0.029	(−0.041 ~−0.017)	<0.001	−0.029	(−0.041 ~−0.017)	<0.001
Survey
2001–2002	0.256	(0.041 ~ 0.471)	0.02	0.294	(0.092 ~ 0.496)	0.005
2003–2004	0.143	(−0.023 ~ 0.309)	0.092	0.193	(0.019 ~ 0.367)	0.03
2005–2006	0.024	(−0.091 ~ 0.139)	0.677	0.088	(−0.026 ~ 0.201)	0.127
2007–2008	−0.016	(−0.162 ~ 0.129)	0.823	−0.03	(−0.165 ~ 0.104)	0.656
2009–2010	Reference			Reference
2011–2012	−0.184	(−0.309 ~−0.059)	0.004	−0.114	(−0.241 ~ 0.014)	0.079
2013–2014	−0.246	(−0.355 ~−0.136)	<0.001	−0.166	(−0.280 ~−0.052)	0.005
2015–2016	−0.168	(−0.351 ~ 0.014)	0.07	−0.2	(−0.407 ~ 0.007)	0.058
2017–2018	−0.183	(−0.391 ~ 0.025)	0.084	−0.133	(−0.346 ~ 0.080)	0.218

Adjusted for age, race/ethnicity, education, and PIR levels. Weighted analysis was performed. OR, odds ratio; CI, confidence interval.