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Table 5 Fixed Effects for Cross-Classified Models

From: A multilevel non-hierarchical study of birth weight and socioeconomic status

   Model III Model IIIa Model IIIb
   β (grams) (SE;P-Value) β (grams) (SE;P-Value) β (grams) (SE;P-Value)
  AIC 21201.52 21243.31 21279.45
Gender Male v Female 158.30(21.62; < 0.001) 159.07(21.57; < 0.001) 160.25(21.60; < 0.001)
Gestational duration Weeks 52.94(6.49; < 0.001) 51.25(6.46; < 0.001) 54.34(6.47; < 0.001)
Birth order - < 0.001 < 0.001 < 0.001
  1v3+ -229.17(34.44; < 0.001) -221.10(33.44; < 0.001) -223.98(34.35; < 0.001)
  2v3+ -145.33(31.21; < 0.001) -141.77(30.69; < 0.001) -139.72(31.13; < 0.001)
Year of birth   0.094 0.093 0.150
  (1975 v 1983) -63.72(53.91;0.239) -63.95(53.91;0.238) -69.04(53.75;0.201)
  (1976 v 1983) 61.63(54.52;0.260) 62.94(54.34;0.249) 46.96(54.30;0.389)
  (1977 v 1983) -61.82(47.24;0.193) -63.26(47.24;0.183) -60.90(47.10;0.198)
  (1978 v 1983) -40.11(44.6;0.370) -40.20(44.55;0.368) -45.58(44.56;0.308)
  (1979 v 1983) -63.04(41.19;0.128) -67.56(41.16;0.103) -64.65(41.14;0.118)
  (1980 v 1983) 37.05(39.51;0.350) 31.98(39.41;0.418) 29.39(39.39;0.457)
  (1981 v 1983) -1.26(41.97;0.976) -4.23(41.93;0.920) -3.79(41.88;0.928)
  (1982 v 1983) -4.98(41.07;0.904) -9.10(41.04;0.825) -9.10(41.01;0.825)
Adequate prenatal care Yes v No 73.98(35.73;0.038) 82.16(35.58;0.021) 71.07(35.66;0.046)
Inadequate weight gain Yes v No -184.84(44.11; < 0.001) -190.94(44.02; < 0.001) -181.72(44.06; < 0.001)
Maternal age Years -3.08(3.28;0.348) -1.91(3.07;0.534) -2.12(3.26;0.516)
Maternal race White v NonWhite 188.19(65.56;0.004) 199.20(65.35;0.002) 189.53(65.20;0.004)
Any diabetes Yes v No 246.00(70.70;0.001) 235.57(70.66;0.001) 242.26(70.33;0.001)
Any hypertension Yes v No -17.51(45.94;0.703) -15.25(45.89;0.740) -23.49(45.72;0.607)
Cervical incompetence Yes v No -151.88(89.70;0.090) -153.72(89.71;0.087) -149.53(89.48;0.095)
Prior low birth weight infant Yes v No -245.43(64.48; < 0.001) -237.67(64.55; < 0.001) -248.83(64.17; < 0.001)
Prior preterm infant Yes v No -14.96(56.14;0.790) -19.73(56.23;0.726) -13.08(55.89;0.815)
Smoking category   < 0.001 < 0.001 < 0.001
  Avg < 10 cig v None -140.06(34.18; < 0.001) -148.57(33.99; < 0.001) -141.18(34.10; < 0.001)
  Avg 11-20 cig v None -212.59(43.57; < 0.001) -219.62(43.41; < 0.001) -212.27(43.39; < 0.001)
  Avg 21+ cig v None -200.75(69.52;0.005) -221.78(69.02;0.002) -209.73(69.21;0.003)
Alcohol consumption   0.945 0.954 0.933
  > = 1 Trimester v None -9.76(37.68;0.796) -9.53(37.53;0.800) -11.34(37.57;0.763)
  3 Trimesters v None -7.59(27.92;0.786) -6.29(27.83;0.821) -7.88(27.84;0.777)
Maternal education   0.242   0.251
  < HS v College -127.67(79.49;0.111)   -129.77(79.30;0.104)
  HS Grad v College 3.31(27.04;0.903)   -2.28(26.84;0.932)
Paternal occupation   0.102   0.085
  Blue v White Collar -46.64(27.35;0.09)   -48.82(27.16;0.075)
  Other v White Collar 22.53(35.25;0.524)   21.88(35.18;0.535)
% Adults living in poverty > 0% v 0% -51.41(28.13;0.068) -50.34(28.01;0.072)  
Mean family income   0.831 0.851  
(quartiles) Q1vQ4 -3.13(37.61;0.934) -10.38(37.33;0.781)  
  Q2vQ4 -0.52(35.04;0.988) 0.33(34.87;0.992)  
  Q3vQ4 -29.79(37.22;0.425) -28.11(37.03;0.449)  
% Adults graduated   0.138 0.124  
4 year college (quartiles) Q1vQ4 -50.49(37.06;0.175) -51.99(36.8;0.16)  
  Q2vQ4 -0.53(34.55;0.988) -3.00(34.41;0.931)  
  Q3vQ4 41.22(37.69;0.276) 41.29(37.52;0.273)  
% Unemployment ≤ 10% v > 10% 19.5(32.54;0.549) 18.84(32.37;0.561)  
  1. Type III p-value for overall variation between categories