Table 5.
Linear regression models of neurobehavioral tests and parent’s occupation (agricultural children vs. non-agricultural) at two time points and change over time, negative coefficients [b] indicate that performance is worse with increasing exposure.
| NB Outcomec | Agricultural children vs. non-agricultural children
|
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|---|---|---|---|---|---|---|
| First visita,d
|
Second visita,d
|
Difference in NB performancee
|
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| N | β (SE) | N | β (SE) | N | β (SE) | |
| Digit span | ||||||
| Forward | 182 | −0.34 (0.15) | 151 | 0.16 (0.18) | 125 | 0.26 (0.19) |
| Reverse | 139 | 0.04 (0.14) | 127 | 0.06 (0.18) | 92 | 0.09 (0.23) |
| Finger tapping | ||||||
| Taps, P | 187 | 2.27 (1.40) | 152 | 0.95 (1.59) | 128 | −1.67 (1.68) |
| Taps, NP | 187 | 2.6 (1.38) | 151 | 1.25 (1.61) | 127 | −1.73 (1.56) |
| Match-to-sample | ||||||
| Number correct | 176 | 0.30 (0.33) | 151 | −0.42 (0.32) | 122 | −0.27 (0.43) |
| Latency | 176 | −79.43 (148.79) | 151 | −17.47 (204.19) | 122 | 57.47 (264.97) |
| Symbol-digit | ||||||
| Latency | 180 | 132.72 (197.19) | 146 | 366.22 (227.36) | 121 | 27.54 (214.00) |
| Continuous performance | ||||||
| Correct Hits | 182 | 0.02 (0.02) | 146 | 0.02 (0.02) | 122 | 0.01 (0.03) |
| d prime | 175 | 0.24 (0.15) | 146 | 0.27 (0.16) | 122 | 0.16 (0.22) |
| Divided attention | ||||||
| Taps, P | 177 | 2.33 (1.33) | 146 | −1.05 (1.53) | 117 | −4.13 (1.92) |
| Taps, NP | 177 | 1.45 (1.32) | 145 | 0.79 (1.36) | 116 | −1.03 (1.49) |
| Taps with song, P | 177 | 1.71 (1.59) | 146 | −0.15 (1.53) | 117 | −3.89 (1.93) |
| Taps with song, NP | 177 | 1.70 (1.30) | 145 | 0.26 (1.39) | 116 | −1.77 (1.45) |
| Times sang song, P taps | 181 | −0.24 (0.12) | 150 | −0.37 (0.14) | 119 | −0.29 (0.16) |
| Times sang song, NP taps | 183 | −0.15 (0.12) | 146 | −0.48 (0.14)b | 121 | −0.36 (0.14) |
| Object memory | ||||||
| Utilization | 198 | 0.65 (0.30) | 155 | 0.10 (0.29) | 134 | −0.70 (0.46) |
| Immediate recall | 198 | −0.38 (0.29) | 155 | 0.58 (0.39) | 134 | 0.77 (0.47) |
| Recognition | 192 | −0.17 (0.29) | 152 | −0.04 (0.14) | 127 | 0.45 (0.26) |
| Purdue pegboard | ||||||
| Pegs, P | 198 | 0.06 (0.23) | 158 | 0.13 (0.28) | 136 | −0.25 (0.32) |
| Pegs, NP | 197 | 0.23 (0.24) | 157 | −0.27 (0.26) | 135 | −0.66 (0.31) |
| Pegs, both | 196 | 0.36 (0.25) | 157 | 0.07 (0.33) | 135 | −0.50 (0.38) |
| Visual motor integration | ||||||
| VMI score | 188 | −0.23 (0.43) | 160 | −0.83 (0.55) | 131 | −0.63 (0.62) |
| Signature test | ||||||
| P Hand | 190 | −1.36 (1.24) | 155 | −1.94 (1.37) | 130 | 1.23 (1.27) |
| NP Hand | 187 | −0.73 (1.76) | 152 | −1.23 (1.93) | 127 | 1.38 (2.71) |
Abbreviations: NB, neurobehavioral; β, regression parameter estimates; SE, standard errors; P, preferred hand; NP, non-preferred hand. Significance (p <0.05) marked in bold numbers and grey cell background.
Models represent the effect of agricultural children vs. non-agricultural children (referent group) on continuous neurobehavioral outcomes [β].
Significant after Bonferroni corrections (p <0.0021) with a p-value = 0.001.
All outcomes have been standardized so that a negative coefficient indicates that performance is worse with increasing exposure.
Parent’s occupation Time 1 and Time 2 models adjusted for age, gender, and CBCL external score.
Longitudinal parent’s occupation models adjusted for HOME score and mother’s education. Additional test-specific confounders include: gender (name writing tests), and computer use (name writing tests and object memory tests).