Table 3.
Univariate associations between sociodemographic/cultural characteristics and blood Pb concentrations (μg/dL) in Samburu, Kenya adolescents
| n | β1 | 95 % CI | Geometric Mean | 95% CI | |
|---|---|---|---|---|---|
| Age (yrs) | |||||
| < 13 | 74 | ref | 2.10 | (1.89, 2.34) | |
| ≥ 13 | 87 | −0.143 | (−0.355, 0.068) | 1.90 | (1.72, 2.11) |
| Sex | |||||
| females | 83 | ref | 1.86 | (1.70, 2.04) | |
| males | 78 | 0.205 | (−0.005, 0.415) | 2.14 | (1.91, 2.40) |
| BMI (kg/m 2 ) | |||||
| <16 | 117 | ref | 2.02 | (1.86,2.19) | |
| ≥ 16 | 44 | −0.068 | (−0.305, 0.170) | 1.93 | (1.64,2.27) |
| Anemia 2 | |||||
| No | 107 | ref | 1.99 | (1.82,2.19) | |
| Yes | 54 | −0.005 | (−0.230, 0.219) | 1.99 | (1.75,2.25) |
| Education (yrs) | |||||
| < 7 | 96 | ref | 1.99 | (1.82, 2.19) | |
| ≥ 7 | 62 | −0. 013 | (−0.231, 0.205) | 1.98 | (1.74, 2.24) |
| Income (Kenya Shillings/month) | |||||
| < 3000 | 96 | ref | 1.84 | (1.68, 2.00) | |
| ≥ 3000 | 65 | 0.291 | (0.08, 0.502) | 2.25 | (1.98, 2.55) |
| Polygyny | |||||
| no | 67 | ref | 2.15 | (1.90, 2.44) | |
| yes | 94 | −0.192 | (−0.405, 0.021) | 1.89 | (1.72, 2.06) |
| Residence | |||||
| highlands | 97 | ref | 2.15 | (1.98, 2.34) | |
| lowlands | 64 | -0.279 | (−0.492, −0.067) | 1.77 | (1.56, 2.02) |
| Number of siblings | |||||
| < 5 | 83 | ref | 1.82 | (1.66, 2.00) | |
| ≥ 5 | 74 | 0.259 | (0.049, 0.469) | 2.18 | (1.94, 2.45) |
| Spending category (Kenya Shillings/month) | |||||
| < 6000 | 88 | ref | 2.06 | (1.88, 2.26) | |
| ≥ 6000 | 73 | −0.106 | (−0.318, 0.107) | 1.91 | (1.70, 2.15) |
| Currently in school | |||||
| no | 43 | ref | 1.67 | (1.45, 1.92) | |
| yes | 118 | 0.348 | (0.115, 0.581) | 2.13 | (1.95, 2.31) |
| Tea consumption (cups) | |||||
| <2 | 137 | ref | 1.96 | (1.81, 2.13) | |
| ≥2 | 23 | 0.136 | (−0.167, 0.440) | 2.16 | (1.82, 2.56) |
| Number of wives | |||||
| <2 | 139 | ref | 2.04 | (1.89, 2.21) | |
| ≥ 2 | 15 | −0.267 | (−0.636, 0.102) | 1.70 | (1.27, 2.27) |
| Tropical Livestock Units | |||||
| <9 | 81 | ref | 2.05 | (1.86, 2.25) | |
| ≥9 | 80 | −0.079 | (−0.290, 0.133) | 1.94 | (1.73, 2.17) |
These parameter estimates are calculated from individual univariate linear regression models examining the association between each characteristic and continuous log2 transformed Pb. For example, compared to children < 13 years of age, children ≥ 13 years of age have 0.143 lower Pb concentrations on the log 2 scale.
Anemia was defined according to the World Health Organization cutoffs of hemoglobin < 12 g/dL for males and females less than 12–14 years of age, < 12 g/dL for females 15 years and older, and < 13 g/dL for males 15 years and older (WHO, 2011).
Abbreviations: Pb lead, GM geometric mean, yrs years
Missing: age n=0, anemia n=2, education n=3, income n=0, polygamous n=0, residence n=0, number of siblings n=4, spending n=0, school n=0, sex n= 0, tea n=1, number of wives n=7, tropical livestock units n=0, birth order n=4
Bolded = statistically significant at p<0.05