TECHNICAL APPENDIX I. VARIABLE DICTIONARY II. SINGLE PREDICTOR REGRESSION ANALYSIS III. PAIRWISE CORRELATION OF TABLE 1 VARIABLES IV. FINAL MODEL REGRESSION ANALYSIS All analyses were performed in Stata 14. I. VARIABLE DICTIONARY: Abbreviation Variable -------------------------------------------------------------------------------- matmor Maternal mortality rate cert Adoption of 2003 Revision of the U.S. Standard Certificate of Death matage35 Proportion of births to women over the age of 35 matage40 Proportion of births to women over the age of 40 medincome Median household income, in thousands chrhtn Proportion of births to women with chronic hypertension diab Proportion of births to women with diabetes prhtn Proportion of births to women with pregnancy-related hypertension csec Proportion of births delivered via cesarean section afammoms Proportion of births to African American women hispmoms Proportion of births to Hispanic women cbafins Uninsurance rate among women of childbearing age cbafobe Proportion of women of childbearing age with BMI ≥ 30 cbafalc Proportion of women of childbearing age reporting alcohol consumption in the previous 30 days cbafsmok Proportion of women of childbearing age who are current smokers chafedu Proportion of women of childbearing age not having completed high school/GED cbafhealth Proportion of women of childbearing age with self-reported health status of “Fair” or “Poor” noprcare Proportion of births to women who attended no prenatal visits u10prcare Proportion of births to women who attended fewer than 10 prenatal visits preterm Proportion of births before 37 weeks gestational age obwf Obstetricians in active patient care, per 100,000 live births II. SINGLE PREDICTOR REGRESSION ANALYSIS mixed matmor cert matage35 || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.846674 .356863 24.79 0.000 8.147235 9.546113 matage35 | .0849566 .1357119 0.63 0.531 -.1810339 .350947 _cons | 9.22552 1.886652 4.89 0.000 5.527749 12.92329 ------------------------------------------------------------------------------ mixed matmor cert matage40 || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.370844 .3684934 22.72 0.000 7.64861 9.093078 matage40 | 1.820359 .4693527 3.88 0.000 .9004444 2.740273 _cons | 6.161802 1.297593 4.75 0.000 3.618567 8.705038 ------------------------------------------------------------------------------ mixed matmor cert medincome || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 7.13826 .4258826 16.76 0.000 6.303545 7.972975 medincome | .2129861 .0316986 6.72 0.000 .1508581 .2751141 _cons | 1.162597 1.562762 0.74 0.457 -1.900361 4.225555 ------------------------------------------------------------------------------ mixed matmor cert chrhtn || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 7.239536 .378234 19.14 0.000 6.498211 7.980861 chrhtn | 3.820076 .4251846 8.98 0.000 2.986729 4.653422 _cons | 6.545508 .7944285 8.24 0.000 4.988457 8.10256 ------------------------------------------------------------------------------ mixed matmor cert diab || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 6.585056 .4362933 15.09 0.000 5.729937 7.440175 diab | 1.237446 .1516343 8.16 0.000 .9402481 1.534644 _cons | 6.107082 .9122386 6.69 0.000 4.319128 7.895037 ------------------------------------------------------------------------------ mixed matmor cert prhtn || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.479184 .3586316 23.64 0.000 7.776279 9.182089 prhtn | .9823135 .2494285 3.94 0.000 .4934426 1.471184 _cons | 6.19262 1.271275 4.87 0.000 3.700966 8.684274 ------------------------------------------------------------------------------ mixed matmor cert csec || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 6.547358 .4248071 15.41 0.000 5.714751 7.379964 csec | .3455264 .0391022 8.84 0.000 .2688876 .4221653 _cons | 1.686423 1.175617 1.43 0.151 -.6177433 3.99059 ------------------------------------------------------------------------------ mixed matmor cert afammoms || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.817914 .345213 25.54 0.000 8.141309 9.494519 afammoms | .2536658 .0323442 7.84 0.000 .1902723 .3170593 _cons | 6.818645 .6396236 10.66 0.000 5.565006 8.072284 ------------------------------------------------------------------------------ mixed matmor cert hispmoms || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.416413 .3679432 22.87 0.000 7.695257 9.137568 hispmoms | .1723803 .0482617 3.57 0.000 .0777892 .2669714 _cons | 8.05918 1.000211 8.06 0.000 6.098803 10.01956 ------------------------------------------------------------------------------ mixed matmor cert cbafins || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.622688 .3598647 23.96 0.000 7.917366 9.32801 cbafins | .137546 .0507185 2.71 0.007 .0381397 .2369524 _cons | 7.767654 1.160475 6.69 0.000 5.493164 10.04214 ------------------------------------------------------------------------------ mixed matmor cert cbafobe || state: Mixed-effects ML regression Number of obs = 815 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 6.529581 .4093354 15.95 0.000 5.727298 7.331864 cbafobe | .3772624 .0389121 9.70 0.000 .300996 .4535288 _cons | 3.243724 .9723913 3.34 0.001 1.337872 5.149576 ------------------------------------------------------------------------------ mixed matmor cert cbafalc || state: Mixed-effects ML regression Number of obs = 737 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.884807 .3659041 24.28 0.000 8.167648 9.601966 cbafalc | .0891217 .0359786 2.48 0.013 .0186049 .1596385 _cons | 5.823603 2.01533 2.89 0.004 1.873628 9.773578 ------------------------------------------------------------------------------ mixed matmor cert cbafsmok || state: Mixed-effects ML regression Number of obs = 815 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.15123 .4016344 20.30 0.000 7.364041 8.938418 cbafsmok | -.177227 .049242 -3.60 0.000 -.2737394 -.0807145 _cons | 14.67426 1.398854 10.49 0.000 11.93256 17.41596 ------------------------------------------------------------------------------ mixed matmor cert cbafedu || state: Mixed-effects ML regression Number of obs = 815 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.531091 .3501444 24.36 0.000 7.84482 9.217361 cbafedu | .3148984 .0668557 4.71 0.000 .1838637 .4459332 _cons | 7.57776 .9117587 8.31 0.000 5.790746 9.364774 ------------------------------------------------------------------------------ mixed matmor cert cbafhealth || state: Mixed-effects ML regression Number of obs = 815 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.06063 .3622061 22.25 0.000 7.35072 8.770541 cbafhealth | .5295531 .0826769 6.41 0.000 .3675094 .6915968 _cons | 5.473034 1.022472 5.35 0.000 3.469027 7.477042 ------------------------------------------------------------------------------ mixed matmor cert noprcare || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 9.057868 .3506175 25.83 0.000 8.37067 9.745065 noprcare | -.6267489 .2703264 -2.32 0.020 -1.156579 -.096919 _cons | 11.00217 .7815407 14.08 0.000 9.470377 12.53396 ------------------------------------------------------------------------------ mixed matmor cert u10prcare || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.724346 .3480089 25.07 0.000 8.042261 9.406431 u10prcare | .1198701 .0352704 3.40 0.001 .0507413 .1889988 _cons | 7.349292 1.104881 6.65 0.000 5.183766 9.514819 ------------------------------------------------------------------------------ mixed matmor cert preterm || state: Mixed-effects ML regression Number of obs = 816 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.877071 .3473873 25.55 0.000 8.196205 9.557938 preterm | .2472369 .1927126 1.28 0.200 -.1304729 .6249467 _cons | 7.361432 2.399303 3.07 0.002 2.658885 12.06398 ------------------------------------------------------------------------------ mixed matmor cert obwf || state: Computing standard errors: Mixed-effects ML regression Number of obs = 765 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 8.871546 .3685374 24.07 0.000 8.149226 9.593866 obwf | .2039154 .1528744 1.33 0.182 -.0957129 .5035436 _cons | 8.495059 1.484426 5.72 0.000 5.585638 11.40448 ------------------------------------------------------------------------------ III. PAIRWISE CORRELATION OF TABLE 1 VARIABLES . pwcorr matage40 medincome chrhtn diab prhtn csec afammoms hispmoms cbafins cbafobe cbafalc cbafsmok cbafedu cbafhealth noprcare u1 > 0prcare | matage40 medinc~e chrhtn diab prhtn csec afammoms -------------+--------------------------------------------------------------- matage40 | 1.0000 medincome | 0.6655 1.0000 chrhtn | 0.0788 0.1869 1.0000 diab | 0.3205 0.5248 0.6238 1.0000 prhtn | -0.4299 -0.1537 0.4650 0.3410 1.0000 csec | 0.1920 0.2943 0.6068 0.4795 0.1349 1.0000 afammoms | 0.0997 -0.1125 0.3244 -0.1397 -0.1206 0.3908 1.0000 hispmoms | 0.2906 0.1853 -0.2669 -0.0081 -0.3995 0.0577 -0.1292 cbafins | -0.3158 -0.2975 -0.0147 -0.1574 0.0721 0.2545 0.0747 cbafobe | -0.2297 0.0635 0.6354 0.4135 0.3650 0.7131 0.3104 cbafalc | 0.5274 0.3683 -0.1371 0.0904 -0.2850 -0.1488 -0.1128 cbafsmok | -0.4630 -0.5463 0.0064 -0.2720 0.2482 -0.2096 -0.0421 cbafedu | -0.1417 -0.1740 -0.0193 -0.0485 -0.0334 0.2287 0.0384 cbafhealth | -0.1425 -0.0951 0.2808 0.1520 0.1485 0.4824 0.1101 noprcare | -0.0771 -0.1010 0.0503 -0.0649 -0.1407 0.2210 0.3050 u10prcare | -0.0122 0.0764 -0.1071 0.0477 -0.1184 -0.0484 -0.0628 | hispmoms cbafins cbafobe cbafalc cbafsmok cbafedu cbafhe~h -------------+--------------------------------------------------------------- hispmoms | 1.0000 cbafins | 0.4493 1.0000 cbafobe | -0.0638 0.3530 1.0000 cbafalc | -0.0155 -0.4601 -0.3780 1.0000 cbafsmok | -0.5089 -0.0950 -0.0429 -0.0197 1.0000 cbafedu | 0.5928 0.6158 0.3083 -0.3296 -0.1037 1.0000 cbafhealth | 0.3786 0.5876 0.5659 -0.4361 -0.0155 0.7087 1.0000 noprcare | 0.3897 0.4098 0.2092 -0.2041 -0.0947 0.3287 0.3407 u10prcare | 0.3301 0.2892 0.0377 -0.0803 -0.2051 0.1179 0.0791 | noprcare u10prc~e -------------+------------------ noprcare | 1.0000 u10prcare | 0.3708 1.0000 IV.FINAL MODEL REGRESSION ANALYSIS mixed matmor cert diab afammoms cbafobe cbafedu u10prcare || state: Mixed-effects ML regression Number of obs = 815 Group variable: state Number of groups = 51 ------------------------------------------------------------------------------ matmor | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- cert | 6.260057 .4331468 14.45 0.000 5.411105 7.109009 diab | .3932337 .1819555 2.16 0.031 .0366075 .74986 afammoms | .2019147 .0338349 5.97 0.000 .1355995 .2682299 cbafobe | .2472718 .0477957 5.17 0.000 .153594 .3409497 cbafedu | .17388 .0622516 2.79 0.005 .0518691 .295891 u10prcare | .0724558 .0325848 2.22 0.026 .0085908 .1363208 _cons | -1.764987 1.216097 -1.45 0.147 -4.148493 .6185186 ------------------------------------------------------------------------------