Skip to main content
. 2020 Jul 8;17(14):4937. doi: 10.3390/ijerph17144937

Table 2.

Two-level Logistic Regression Models of Early Developmental Milestones on Individual and County-level Variables.

Walk Alone (in Months) First Sentences (in Months) Count 10 Objects (in Months) Independent Toileting (in Months)
(1) (2) (3) (4) (5) (1) (2) (3) (4) (5) (1) (2) (3) (4) (5) (1) (2) (3) (4) (5)
Individual-level coefficients
Maternal education −0.071 *** −0.062 *** −0.302 ** −0.153 *** −0.144 *** −0.711 ** −0.442 *** −0.404 *** −1.564 *** −0.222 *** −0.206 *** −1.245 ***
(0.012) (0.013) (0.115) (0.021) (0.025) (0.228) (0.037) (0.045) (0.415) (0.032) (0.039) (0.362)
Female −0.100 −0.103 −0.105 −0.866 *** −0.871 *** −0.878 *** −1.076 *** −1.087 *** −1.101 *** −0.800 *** −0.790 *** −0.796 ***
(0.078) (0.078) (0.078) (0.142) (0.142) (0.142) (0.249) (0.248) (0.248) (0.214) (0.213) (0.213)
Birth Cohort (Ref: 1995–1999)
2000–2004 −0.391 *** −0.394 *** −0.400 *** −0.644 ** −0.622 ** −0.634 ** −0.437 −0.426 −0.448 −0.297 −0.282 −0.299
(0.119) (0.119) (0.119) (0.210) (0.210) (0.210) (0.365) (0.364) (0.364) (0.318) (0.318) (0.318)
2005–2009 −1.036 *** −1.024 *** −1.029 *** −1.491 *** −1.480 *** −1.490 *** −4.575 *** −4.597 *** −4.617 *** −5.261 *** −5.274 *** −5.292 ***
(0.118) (0.118) (0.118) (0.210) (0.210) (0.210) (0.370) (0.370) (0.370) (0.319) (0.318) (0.318)
After 2010 −1.193 *** −1.191 *** −1.196 *** −1.485 *** −1.482 *** −1.491 *** −5.131 *** −5.116 *** −5.139 *** −5.969 *** −5.979 *** −5.994 ***
(0.118) (0.118) (0.118) (0.216) (0.215) (0.215) (0.377) (0.377) (0.377) (0.324) (0.324) (0.324)
Minority 0.473 ** 0.361* 0.359* −0.121 −0.160 −0.167 −0.697 −0.575 −0.608 −0.062 0.052 0.042
(0.168) (0.167) (0.167) (0.316) (0.315) (0.315) (0.559) (0.560) (0.559) (0.479) (0.472) (0.471)
Birth Weight (Ref: Normal Weight)
Low birth weight 0.769 *** 0.769 *** 0.767 *** 1.640 *** 1.652 *** 1.648 *** 2.103 *** 2.081 *** 2.068 *** 1.540 ** 1.617 ** 1.611 **
(0.186) (0.185) (0.185) (0.333) (0.333) (0.333) (0.592) (0.591) (0.591) (0.503) (0.502) (0.502)
Unknown 1.309 *** 1.323 *** 1.297 *** 1.255 *** 1.275 *** 1.227 *** 5.683 *** 5.659 *** 5.561 *** 2.499 *** 2.545 *** 2.462 ***
(0.149) (0.150) (0.150) (0.263) (0.265) (0.266) (0.465) (0.468) (0.469) (0.405) (0.407) (0.408)
Gestational Age (Ref: ≥37 Weeks)
<37 weeks 0.691 ** 0.717 *** 0.713 *** −0.048 0.008 0.006 −0.370 −0.372 −0.374 −0.221 −0.224 −0.231
(0.211) (0.210) (0.210) (0.383) (0.382) (0.382) (0.683) (0.682) (0.682) (0.586) (0.585) (0.584)
Urban hukou before age 3 −0.296 * −0.296 * −0.315 * −0.334 −0.341 −0.389 −2.484 *** −2.558 *** −2.654 *** −0.565 −0.556 −0.629 †
(0.127) (0.127) (0.127) (0.237) (0.236) (0.237) (0.413) (0.413) (0.414) (0.353) (0.352) (0.352)
Maternal Age at Delivery (Ref: <20)
20–24 0.047 0.055 0.052 −0.263 −0.270 −0.275 0.661 0.592 0.583 0.007 −0.014 −0.020
(0.221) (0.221) (0.221) (0.399) (0.398) (0.398) (0.703) (0.702) (0.702) (0.604) (0.603) (0.603)
25–29 0.130 0.139 0.129 −0.069 −0.066 −0.085 1.159 1.113 1.081 0.250 0.235 0.205
(0.223) (0.222) (0.222) (0.402) (0.401) (0.401) (0.708) (0.707) (0.707) (0.609) (0.607) (0.607)
30–34 0.224 0.251 0.245 0.041 0.059 0.050 1.526 * 1.523 * 1.506 * 0.470 0.466 0.451
(0.235) (0.234) (0.234) (0.424) (0.423) (0.423) (0.748) (0.747) (0.746) (0.641) (0.640) (0.639)
35+ 0.327 0.357 0.358 0.127 0.175 0.183 1.472 † 1.558 † 1.569 † −0.663 −0.608 −0.604
(0.263) (0.262) (0.262) (0.477) (0.476) (0.476) (0.843) (0.843) (0.842) (0.717) (0.716) (0.716)
County-Level Coefficients
Ln (GDP per capita) −0.581 *** −0.453 *** −0.411 *** −0.469 *** −0.549 ** −0.437 * −0.298 † −0.436 * −2.072 *** −1.594 *** −1.444 *** −1.668 *** −0.402 −0.130 0.109 −0.196
(0.088) (0.084) (0.079) (0.084) (0.178) (0.175) (0.165) (0.174) (0.333) (0.310) (0.298) (0.309) (0.281) (0.269) (0.244) (0.266)
Urban population % −0.003 −0.001 −0.000 −0.000 −0.005 −0.001 −0.003 −0.002 −0.068 *** −0.047 *** −0.042 *** −0.040 ** −0.028 * −0.026 * −0.025 * −0.023 *
(0.004) (0.004) (0.003) (0.003) (0.007) (0.007) (0.007) (0.007) (0.013) (0.013) (0.012) (0.012) (0.011) (0.011) (0.010) (0.010)
Cross-Level Interaction Coefficients
Maternal education × Ln (GDP per capita) 0.024 * 0.058 * 0.118 ** 0.105 **
(0.012) (0.023) (0.042) (0.036)
Constant 13.940 *** 19.917 *** 19.054 *** 18.618 *** 19.217 *** 20.120 *** 25.796 *** 25.950 *** 24.574 *** 25.982 *** 32.441 *** 55.737 *** 52.607 *** 50.961 *** 53.270 *** 31.364 *** 36.291 *** 36.709 *** 34.247 *** 37.344 ***
(0.088) (0.842) (0.836) (0.781) (0.832) (0.161) (1.703) (1.716) (1.621) (1.713) (0.367) (3.181) (3.043) (2.931) (3.042) (0.253) (2.684) (2.644) (2.406) (2.632)
N 11,361 11,361 11,361 11,361 11,361 10,324 10,324 10,324 10,324 10,324 10,061 10,061 10,061 10,061 10,061 10,751 10,751 10,751 10,751 10,751

Notes. Standard errors in parentheses; † p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001.