Annex to
Preventing obesity in the US: impact on health service utilization and costs
This annex to the paper titled: “Preventing obesity in the US: impact on health service utilization and costs” reports a technical appendix providing:
- A description of the selection process we used to select and validate the econometric approach
- the specification of the distributions used to model the nine equations
- Full output details of all the models employed in the analyses. In particular, for each of the models described in the paper, this technical appendix reports STATA outputs with coefficients, confidence intervals and model specification tests.
Part 1 - Selection of the econometric approach
The approach used in the analyses was compared to other four approaches: the RAND log-transformed four-part model (RAND-T), a modified version of the RAND four-part model using a generalized linear model (GLM) (RAND-GLM), a two-part regression approach using GLM (2PART) and a six-part regression approach by healthcare service using GLM (6PART). For each of the assessed econometric models, table A.1 reports the underlying algorithm. We have also considered other common approaches: the log-transformed single-part linear model, the square-root transformed single-part linear model, the square-root transformed two-part model, the untransformed two-part model. However, results from previous studies show that there is clear and consistent evidence of poorer performances and, therefore, these approaches were discarded before the testing exercise.
Table A.1 – specifications of the assessed models
Name / Model specificationRAND-T & RAND-V /
2PART /
6PART /
These analyses /
Legend / TOTEXP: tot expenditure / AVEXP: expend. per episode / EXP: expenditure / PR: probability
INP: inpatient / NIP: non-inpatient / OUTP: outpatient / DRU: drug
N: number
All the models include two vectors of covariates with socio-demographic conditions and medical conditions. A third vector of variables was model-specific and included dimensions associated with the type and the quantity of healthcare services that were used by patients.
The models were compared and assessed on their predictive ability of goodness of fit statistics using a standard set of criteria. Given the high heterogeneity of the considered models, particularly in terms of their outputs, the assessment was limited to the prediction of total annual healthcare expenditure. The indicators on which the econometric approaches were primarily tested include: i) the average and the standard deviation; ii) the root mean squared error (RMSE); iii) the mean absolute prediction error (MAPE); iv) the mean prediction error (MPE); v) the scale-free Theil’s statistics (SFTS); vi) the ratio between the predicted healthcare expenditure and the original data by decile of predicted healthcare expenditure. Results of the key tests are presented in table A.2 and figure A.1
TableA.2. Descriptive statistics of original and predicted total expenditure
Regressionapproach / starting data / predicted data
mean / Mean
[low CI] / Mean
[up CI] / stddev / mean / Mean
[low CI] / Mean
[up CI] / stddev
RAND-T / 4559 / 4508 / 4610 / 11336 / 3067 / 3045 / 3089 / 4938
RAND -V / 4359 / 4312 / 4406 / 10955 / 2789 / 2771 / 2806 / 4031
2PART / 3982 / 3939 / 4025 / 10543 / 4673 / 4623 / 4723 / 12187
6PART / 4044 / 3997 / 4092 / 11519 / 4414 / 4384 / 4443 / 7177
9PART / 3412 / 3393 / 3430 / 4614 / 4044 / 3997 / 4092 / 11519
Figure A.1 Predicted-original healthcare expenditure ratio bydecile of predicted healthcare expenditure
Part 2 – specifications of the models and process
Dependent variable / Regression approach / link / distribution / CharacterizationPrINP / Logistic regression / - / Logit / Logit(x)~N(0,1)
PrOUTP / Logistic regression / - / Logit / Logit(x)~N(0,1)
PrDRU / Logistic regression / - / Logit / Logit(x)~N(0,1)
NINP / Generalized linear model / Log / Gamma / x~Γ(k,θ)
NOUTP / Generalized linear model / Log / Poisson / x~Pois(λ)
NDRU / Generalized linear model / Log / Gamma / x~Γ(k,θ)
EXPINP / Generalized linear model / Log / Gamma / x~Γ(k,θ)
EXPOUTP / Generalized linear model / Log / Gamma / x~Γ(k,θ)
EXPDRU / Generalized linear model / log / Gamma / x~Γ(k,θ)
For each of the GLM models, the selection of the dependant variable and the link function to determine the relation between the dependant variable and the explanatory variables has followed a two-step approach.
In a first phase, we used the Box-Cox test to select the link between the dependent and the explanatory variables. For all the tested approaches the log link resulted the most suitable option.
In a second phasewe used the Akaike information criterion to identify the best fittinglog link-distribution. For all the outcomes we tested the combination log-link with all the following distribution families: Gaussian, inverse Gaussian, binomial, Poisson, negative binomial and gamma. Log-link and Gamma distribution resulted the most suitable association for all the GLM regressions but “number of outpatient visits” for which, instead, we used the combination of log-link and Poisson distribution.
Part 3 – output data of the regressions
Probability of drug prescription
Number of strata = 419 / Number of obs = 235582Number of PSUs = 2166 / Population size = 2243554589
Design df = 1747
F( 54, 1694) = 232.31
Prob > F = 0.0000
OR / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 0.960241 / 0.053633 / -0.73 / 0.468 / 0.860607 / 1.07141
Year 1999 / 0.941542 / 0.052422 / -1.08 / 0.279 / 0.844141 / 1.050181
Year 2000 / 1.128582 / 0.055247 / 2.47 / 0.014 / 1.025263 / 1.242312
Year 2001 / 1.310069 / 0.069667 / 5.08 / 0 / 1.180314 / 1.454088
Year 2002 / 1.223356 / 0.064098 / 3.85 / 0 / 1.103882 / 1.355759
Year 2003 / 1.165743 / 0.063462 / 2.82 / 0.005 / 1.047688 / 1.2971
Year 2004 / 1.120714 / 0.061465 / 2.08 / 0.038 / 1.006419 / 1.24799
Year 2005 / 1.109103 / 0.061428 / 1.87 / 0.062 / 0.994936 / 1.23637
Year 2006 / 1.047613 / 0.056736 / 0.86 / 0.391 / 0.942042 / 1.165015
Year 2007 / 1.006822 / 0.05576 / 0.12 / 0.902 / 0.903188 / 1.122347
Year 2008 / 0.962088 / 0.052634 / -0.71 / 0.48 / 0.864201 / 1.071061
Year 2009 / 0.935176 / 0.050736 / -1.24 / 0.217 / 0.840778 / 1.040173
Year 2010 / 0.80641 / 0.044996 / -3.86 / 0 / 0.722816 / 0.899672
Gender male / baseline
Gender female / 1.976008 / 0.030982 / 43.44 / 0 / 1.916166 / 2.037718
Age group 0-10 / baseline
Age group 11-20 / 0.693287 / 0.028095 / -9.04 / 0 / 0.640317 / 0.750639
Age group 21-30 / 0.717505 / 0.037168 / -6.41 / 0 / 0.648187 / 0.794235
Age group 31-40 / 0.662028 / 0.036294 / -7.52 / 0 / 0.594537 / 0.73718
Age group 41-50 / 0.681293 / 0.037928 / -6.89 / 0 / 0.610822 / 0.759896
Age group 51-60 / 0.843701 / 0.048796 / -2.94 / 0.003 / 0.753225 / 0.945044
Age group 61-70 / 1.128852 / 0.073678 / 1.86 / 0.063 / 0.993213 / 1.283016
Age group 71-80 / 1.41722 / 0.099927 / 4.95 / 0 / 1.234178 / 1.627407
Age group 81+ / 1.760476 / 0.180171 / 5.53 / 0 / 1.44031 / 2.151811
Race white non-Hispanic / baseline
Race white Hispanic / 0.659183 / 0.016164 / -17 / 0 / 0.628232 / 0.69166
Race Black / 0.663454 / 0.01628 / -16.72 / 0 / 0.632279 / 0.696166
Race Asian / 0.516445 / 0.02008 / -16.99 / 0 / 0.478525 / 0.557369
Race others / 0.789194 / 0.043469 / -4.3 / 0 / 0.70838 / 0.879227
No degree / baseline
High school or less / 0.964413 / 0.021881 / -1.6 / 0.11 / 0.922437 / 1.008299
Bachelor degree / 1.127455 / 0.03306 / 4.09 / 0 / 1.064443 / 1.194197
Master degree or more / 1.219003 / 0.04564 / 5.29 / 0 / 1.132695 / 1.311887
Below poverty line / baseline
1.01 to 1.24 times poverty line / 0.976861 / 0.039322 / -0.58 / 0.561 / 0.902705 / 1.05711
1.25 to 1.99 times poverty line / 0.958667 / 0.029171 / -1.39 / 0.166 / 0.903128 / 1.017622
2.0 to 3.99 times poverty line / 1.045661 / 0.029143 / 1.6 / 0.109 / 0.990035 / 1.104411
4.00 or more times poverty line / 1.191752 / 0.03533 / 5.92 / 0 / 1.124435 / 1.2631
Private insurance / baseline
Public insurance only / 1.1148 / 0.029523 / 4.1 / 0 / 1.058375 / 1.174235
Uninsured / 0.426268 / 0.01059 / -34.32 / 0 / 0.405995 / 0.447553
Single / baseline
Married / 1.133891 / 0.026564 / 5.36 / 0 / 1.082969 / 1.187207
Widow/divorced/separated / 1.042181 / 0.03323 / 1.3 / 0.195 / 0.979003 / 1.109436
Region northeast / baseline
Region midwest / 0.997555 / 0.029212 / -0.08 / 0.933 / 0.941875 / 1.056527
Region south / 1.144604 / 0.031295 / 4.94 / 0 / 1.084842 / 1.207659
Region west / 0.840039 / 0.025816 / -5.67 / 0 / 0.790901 / 0.892229
Body Mass index / 1.008868 / 0.001436 / 6.2 / 0 / 1.006056 / 1.011687
Have hypertension / 7.799568 / 0.359499 / 44.56 / 0 / 7.125406 / 8.537515
Have high cholesterol / 4.612888 / 0.21912 / 32.19 / 0 / 4.202535 / 5.063309
Have diabetes / 7.267646 / 0.551371 / 26.14 / 0 / 6.26284 / 8.433662
Have IHD / 2.586813 / 0.470251 / 5.23 / 0 / 1.811006 / 3.694964
Have stroke / 2.208712 / 0.401941 / 4.35 / 0 / 1.545719 / 3.156079
Have colorectal cancer / 1.0454 / 0.250611 / 0.19 / 0.853 / 0.653258 / 1.672938
Have lung cancer / 1.769363 / 0.620199 / 1.63 / 0.104 / 0.889706 / 3.518745
Have breast cancer / 2.13414 / 0.380646 / 4.25 / 0 / 1.50417 / 3.027951
Have other comorbidities / 3.305391 / 0.197566 / 20 / 0 / 2.93975 / 3.716509
Health status excellent / baseline
Health status very good / 1.389332 / 0.02528 / 18.07 / 0 / 1.340625 / 1.439809
Health status good / 2.00144 / 0.044043 / 31.53 / 0 / 1.916894 / 2.089714
Health status fair / 3.193893 / 0.122525 / 30.27 / 0 / 2.962399 / 3.443476
Health status poor / 5.15338 / 0.499814 / 16.91 / 0 / 4.26068 / 6.233119
Constant / 0.178158 / 0.01503 / -20.45 / 0 / 0.150989 / 0.210216
Number of drug prescriptions
Number of strata = 419 / Number of obs = 177813Number of PSUs = 2057 / Population size = 1737287256
Design df = 1638
coefficient / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 0.008357 / 0.039753 / 0.21 / 0.834 / -0.06961 / 0.086329
Year 1999 / 0.026552 / 0.038446 / 0.69 / 0.49 / -0.04886 / 0.101961
Year 2000 / 0.093828 / 0.033069 / 2.84 / 0.005 / 0.028966 / 0.158691
Year 2001 / 0.174216 / 0.034862 / 5 / 0 / 0.105837 / 0.242595
Year 2002 / 0.22128 / 0.03553 / 6.23 / 0 / 0.151592 / 0.290968
Year 2003 / 0.231003 / 0.036528 / 6.32 / 0 / 0.159357 / 0.302649
Year 2004 / 0.23859 / 0.037036 / 6.44 / 0 / 0.165948 / 0.311232
Year 2005 / 0.247455 / 0.036069 / 6.86 / 0 / 0.176709 / 0.318201
Year 2006 / 0.236058 / 0.035304 / 6.69 / 0 / 0.166811 / 0.305304
Year 2007 / 0.179197 / 0.035058 / 5.11 / 0 / 0.110433 / 0.247961
Year 2008 / 0.143281 / 0.035984 / 3.98 / 0 / 0.072701 / 0.21386
Year 2009 / 0.155553 / 0.036538 / 4.26 / 0 / 0.083887 / 0.227219
Year 2010 / 0.123055 / 0.037004 / 3.33 / 0.001 / 0.050476 / 0.195635
Gender male / baseline
Gender female / 0.211611 / 0.008359 / 25.32 / 0 / 0.195216 / 0.228005
Age group 0-10 / baseline
Age group 11-20 / 0.149508 / 0.027166 / 5.5 / 0 / 0.096224 / 0.202792
Age group 21-30 / 0.228909 / 0.031934 / 7.17 / 0 / 0.166273 / 0.291544
Age group 31-40 / 0.401912 / 0.032707 / 12.29 / 0 / 0.337761 / 0.466063
Age group 41-50 / 0.609313 / 0.032079 / 18.99 / 0 / 0.546392 / 0.672233
Age group 51-60 / 0.805883 / 0.03152 / 25.57 / 0 / 0.74406 / 0.867706
Age group 61-70 / 0.865428 / 0.031924 / 27.11 / 0 / 0.802812 / 0.928043
Age group 71-80 / 0.907309 / 0.033127 / 27.39 / 0 / 0.842334 / 0.972284
Age group 81+ / 1.006021 / 0.035319 / 28.48 / 0 / 0.936746 / 1.075295
Race white non-Hispanic / baseline
Race white Hispanic / -0.3246 / 0.01427 / -22.75 / 0 / -0.35259 / -0.29661
Race Black / -0.28668 / 0.013276 / -21.59 / 0 / -0.31272 / -0.26064
Race Asian / -0.39478 / 0.021908 / -18.02 / 0 / -0.43775 / -0.35181
Race others / -0.05926 / 0.031617 / -1.87 / 0.061 / -0.12128 / 0.002752
No degree / baseline
High school or less / 0.020478 / 0.010723 / 1.91 / 0.056 / -0.00055 / 0.041511
Bachelor degree / 0.079543 / 0.013439 / 5.92 / 0 / 0.053184 / 0.105902
Master degree or more / 0.083903 / 0.017047 / 4.92 / 0 / 0.050468 / 0.117339
Below poverty line / baseline
1.01 to 1.24 times pov line / -0.01867 / 0.019226 / -0.97 / 0.332 / -0.05638 / 0.019039
1.25 to 1.99 times pov line / -0.01831 / 0.014984 / -1.22 / 0.222 / -0.0477 / 0.011079
2.0 to 3.99 times pov line / -0.01782 / 0.014279 / -1.25 / 0.212 / -0.04582 / 0.010191
4.00 or more times pov line / 0.00547 / 0.015319 / 0.36 / 0.721 / -0.02458 / 0.035517
Private insurance / baseline
Public insurance only / 0.182466 / 0.011698 / 15.6 / 0 / 0.159522 / 0.205409
Uninsured / -0.29156 / 0.016119 / -18.09 / 0 / -0.32318 / -0.25995
Single / baseline
Married / -0.11949 / 0.014593 / -8.19 / 0 / -0.14811 / -0.09087
Widow/divorced/separated / -0.02767 / 0.015455 / -1.79 / 0.074 / -0.05799 / 0.002641
Region northeast / baseline
Region midwest / 0.07424 / 0.015154 / 4.9 / 0 / 0.044517 / 0.103962
Region south / 0.08699 / 0.014947 / 5.82 / 0 / 0.057673 / 0.116308
Region west / -0.0247 / 0.014857 / -1.66 / 0.097 / -0.05385 / 0.004437
Body Mass index / 0.003526 / 0.000615 / 5.73 / 0 / 0.00232 / 0.004732
Have hypertension / 0.457415 / 0.008546 / 53.52 / 0 / 0.440652 / 0.474178
Have high cholesterol / 0.317417 / 0.009436 / 33.64 / 0 / 0.29891 / 0.335923
Have diabetes / 0.47703 / 0.010332 / 46.17 / 0 / 0.456765 / 0.497296
Have IHD / 0.243455 / 0.022194 / 10.97 / 0 / 0.199923 / 0.286987
Have stroke / 0.187277 / 0.026146 / 7.16 / 0 / 0.135993 / 0.23856
Have colorectal cancer / 0.097514 / 0.071642 / 1.36 / 0.174 / -0.04301 / 0.238033
Have lung cancer / 0.105761 / 0.070494 / 1.5 / 0.134 / -0.03251 / 0.244029
Have breast cancer / 0.116634 / 0.035612 / 3.28 / 0.001 / 0.046783 / 0.186484
Have other comorbidities / 0.40865 / 0.018085 / 22.6 / 0 / 0.373178 / 0.444122
Health status excellent / baseline
Health status very good / 0.230459 / 0.011053 / 20.85 / 0 / 0.208779 / 0.252139
Health status good / 0.571268 / 0.01235 / 46.26 / 0 / 0.547044 / 0.595492
Health status fair / 0.98756 / 0.015525 / 63.61 / 0 / 0.95711 / 1.01801
Health status poor / 1.363638 / 0.021235 / 64.22 / 0 / 1.321988 / 1.405288
Constant / 0.318997 / 0.03895 / 8.19 / 0 / 0.2426 / 0.395394
Cost per drug prescription
Number of strata = 419 / Number of obs = 177813Number of PSUs = 2057 / Population size = 1737287256
Design df = 1638
coefficient / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 0.025663 / 0.033267 / 0.77 / 0.441 / -0.03959 / 0.090914
Year 1999 / 0.031026 / 0.031895 / 0.97 / 0.331 / -0.03153 / 0.093586
Year 2000 / 0.099552 / 0.040564 / 2.45 / 0.014 / 0.01999 / 0.179115
Year 2001 / 0.171574 / 0.038284 / 4.48 / 0 / 0.096484 / 0.246665
Year 2002 / 0.16914 / 0.038879 / 4.35 / 0 / 0.092882 / 0.245398
Year 2003 / 0.253339 / 0.039678 / 6.38 / 0 / 0.175515 / 0.331163
Year 2004 / 0.235192 / 0.038532 / 6.1 / 0 / 0.159614 / 0.31077
Year 2005 / 0.2521 / 0.040136 / 6.28 / 0 / 0.173376 / 0.330824
Year 2006 / 0.206099 / 0.04038 / 5.1 / 0 / 0.126897 / 0.285301
Year 2007 / 0.261475 / 0.04065 / 6.43 / 0 / 0.181743 / 0.341206
Year 2008 / 0.257483 / 0.040456 / 6.36 / 0 / 0.178132 / 0.336834
Year 2009 / 0.231384 / 0.042882 / 5.4 / 0 / 0.147274 / 0.315495
Year 2010 / 0.209826 / 0.043859 / 4.78 / 0 / 0.1238 / 0.295852
Gender male / baseline
Gender female / -0.08911 / 0.00924 / -9.64 / 0 / -0.10723 / -0.07099
Age group 0-10 / baseline
Age group 11-20 / 0.31252 / 0.035012 / 8.93 / 0 / 0.243846 / 0.381194
Age group 21-30 / 0.25909 / 0.046495 / 5.57 / 0 / 0.167895 / 0.350285
Age group 31-40 / 0.375073 / 0.048222 / 7.78 / 0 / 0.28049 / 0.469656
Age group 41-50 / 0.411504 / 0.047274 / 8.7 / 0 / 0.318782 / 0.504227
Age group 51-60 / 0.426746 / 0.047959 / 8.9 / 0 / 0.332678 / 0.520813
Age group 61-70 / 0.457817 / 0.047718 / 9.59 / 0 / 0.364221 / 0.551412
Age group 71-80 / 0.454744 / 0.047367 / 9.6 / 0 / 0.361838 / 0.54765
Age group 81+ / 0.395322 / 0.047407 / 8.34 / 0 / 0.302337 / 0.488307
Race white non-Hispanic / baseline
Race white Hispanic / -0.05203 / 0.017656 / -2.95 / 0.003 / -0.08666 / -0.0174
Race Black / -0.04697 / 0.015254 / -3.08 / 0.002 / -0.07689 / -0.01705
Race Asian / 0.001252 / 0.029371 / 0.04 / 0.966 / -0.05636 / 0.05886
Race others / -0.02421 / 0.029942 / -0.81 / 0.419 / -0.08294 / 0.034516
No degree / baseline
High school or less / 0.069338 / 0.012715 / 5.45 / 0 / 0.044399 / 0.094276
Bachelor degree / 0.115321 / 0.016544 / 6.97 / 0 / 0.082873 / 0.14777
Master degree or more / 0.142467 / 0.021647 / 6.58 / 0 / 0.100009 / 0.184925
Below poverty line / baseline
1.01 to 1.24 times pov line / -0.00539 / 0.023699 / -0.23 / 0.82 / -0.05188 / 0.041089
1.25 to 1.99 times pov line / 0.004374 / 0.015334 / 0.29 / 0.775 / -0.0257 / 0.03445
2.0 to 3.99 times pov line / 0.027004 / 0.013674 / 1.97 / 0.048 / 0.000183 / 0.053825
4.00 or more times pov line / 0.085782 / 0.01499 / 5.72 / 0 / 0.05638 / 0.115184
Private insurance / baseline
Public insurance only / -0.06099 / 0.012401 / -4.92 / 0 / -0.08531 / -0.03666
Uninsured / -0.1545 / 0.017284 / -8.94 / 0 / -0.1884 / -0.12059
Single / baseline
Married / -0.07664 / 0.017705 / -4.33 / 0 / -0.11136 / -0.04191
Widow/divorced/separated / -0.09844 / 0.01841 / -5.35 / 0 / -0.13455 / -0.06233
Region northeast / baseline
Region midwest / -0.06585 / 0.014646 / -4.5 / 0 / -0.09457 / -0.03712
Region south / -0.05036 / 0.013372 / -3.77 / 0 / -0.07659 / -0.02414
Region west / -0.07404 / 0.015473 / -4.79 / 0 / -0.10439 / -0.04369
Body Mass index / -0.00358 / 0.000716 / -5 / 0 / -0.00498 / -0.00217
Have hypertension / -0.16713 / 0.010212 / -16.37 / 0 / -0.18716 / -0.1471
Have high cholesterol / 0.130392 / 0.009439 / 13.81 / 0 / 0.111878 / 0.148906
Have diabetes / 0.012348 / 0.01236 / 1 / 0.318 / -0.0119 / 0.036591
Have IHD / -0.05952 / 0.026454 / -2.25 / 0.025 / -0.11141 / -0.00764
Have stroke / 0.003235 / 0.024624 / 0.13 / 0.895 / -0.04506 / 0.051532
Have colorectal cancer / -0.02558 / 0.065754 / -0.39 / 0.697 / -0.15455 / 0.103392
Have lung cancer / 0.272516 / 0.094467 / 2.88 / 0.004 / 0.087226 / 0.457805
Have breast cancer / 0.294425 / 0.044788 / 6.57 / 0 / 0.206577 / 0.382273
Have other comorbidities / -0.0853 / 0.029189 / -2.92 / 0.004 / -0.14255 / -0.02805
Number prescriptions 0 / baseline
Number prescriptions 1 / 0.070421 / 0.017857 / 3.94 / 0 / 0.035396 / 0.105446
Number prescriptions 2 / 0.2475 / 0.017915 / 13.82 / 0 / 0.212361 / 0.282639
Number prescriptions 3-5 / 0.356626 / 0.017453 / 20.43 / 0 / 0.322393 / 0.390859
Number prescriptions 6-10 / 0.428746 / 0.017309 / 24.77 / 0 / 0.394796 / 0.462695
Number prescriptions 11+ / 0.439604 / 0.016836 / 26.11 / 0 / 0.406582 / 0.472625
Health status excellent / baseline
Health status very good / 0.025284 / 0.013431 / 1.88 / 0.06 / -0.00106 / 0.051628
Health status good / 0.082895 / 0.014758 / 5.62 / 0 / 0.053949 / 0.11184
Health status fair / 0.152535 / 0.020852 / 7.32 / 0 / 0.111636 / 0.193434
Health status poor / 0.228204 / 0.032796 / 6.96 / 0 / 0.163877 / 0.292531
Constant / 3.639573 / 0.045465 / 80.05 / 0 / 3.550397 / 3.728748
Probability of outpatient visits
Number of strata = 419 / Number of obs = 235582Number of PSUs = 2166 / Population size = 2243554589
Design df = 1747
F( 54, 1694) = 204.57
Prob > F = 0.0000
OR / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 0.97045 / 0.069048 / -0.42 / 0.673 / 0.844049 / 1.115779
Year 1999 / 0.990199 / 0.068642 / -0.14 / 0.887 / 0.864321 / 1.134409
Year 2000 / 0.903611 / 0.054085 / -1.69 / 0.091 / 0.803523 / 1.016165
Year 2001 / 0.926272 / 0.056608 / -1.25 / 0.21 / 0.821642 / 1.044226
Year 2002 / 1.010369 / 0.061168 / 0.17 / 0.865 / 0.897247 / 1.137753
Year 2003 / 0.963625 / 0.058919 / -0.61 / 0.545 / 0.854725 / 1.086399
Year 2004 / 0.88609 / 0.056246 / -1.91 / 0.057 / 0.782365 / 1.003567
Year 2005 / 0.90926 / 0.056641 / -1.53 / 0.127 / 0.804686 / 1.027423
Year 2006 / 0.926103 / 0.057374 / -1.24 / 0.215 / 0.820143 / 1.045753
Year 2007 / 0.884373 / 0.055916 / -1.94 / 0.052 / 0.78123 / 1.001133
Year 2008 / 0.869318 / 0.054799 / -2.22 / 0.026 / 0.768219 / 0.983722
Year 2009 / 0.819886 / 0.05232 / -3.11 / 0.002 / 0.723431 / 0.929202
Year 2010 / 0.846901 / 0.053662 / -2.62 / 0.009 / 0.74793 / 0.958968
Gender male / baseline
Gender female / 2.113987 / 0.035658 / 44.38 / 0 / 2.045194 / 2.185094
Age group 0-10 / baseline
Age group 11-20 / 0.540455 / 0.028356 / -11.73 / 0 / 0.487605 / 0.599032
Age group 21-30 / 0.451553 / 0.027702 / -12.96 / 0 / 0.400362 / 0.509289
Age group 31-40 / 0.462534 / 0.029495 / -12.09 / 0 / 0.408157 / 0.524156
Age group 41-50 / 0.473904 / 0.03045 / -11.62 / 0 / 0.417792 / 0.537553
Age group 51-60 / 0.558212 / 0.036276 / -8.97 / 0 / 0.491411 / 0.634094
Age group 61-70 / 0.740988 / 0.053155 / -4.18 / 0 / 0.643736 / 0.852934
Age group 71-80 / 1.029507 / 0.078913 / 0.38 / 0.704 / 0.885806 / 1.19652
Age group 81+ / 1.116363 / 0.105242 / 1.17 / 0.243 / 0.927908 / 1.343093
Race white non-Hispanic / baseline
Race white Hispanic / 0.728409 / 0.018027 / -12.8 / 0 / 0.693896 / 0.764637
Race Black / 0.646074 / 0.016477 / -17.13 / 0 / 0.614551 / 0.679213
Race Asian / 0.613504 / 0.02645 / -11.33 / 0 / 0.563759 / 0.667638
Race others / 0.799117 / 0.050578 / -3.54 / 0 / 0.705827 / 0.904736
No degree / baseline
High school or less / 1.03104 / 0.023577 / 1.34 / 0.181 / 0.985819 / 1.078334
Bachelor degree / 1.44272 / 0.043903 / 12.04 / 0 / 1.35913 / 1.53145
Master degree or more / 1.726868 / 0.072453 / 13.02 / 0 / 1.590454 / 1.874982
Below poverty line / baseline
1.01 to 1.24 times poverty line / 0.966765 / 0.038807 / -0.84 / 0.4 / 0.893571 / 1.045955
1.25 to 1.99 times poverty line / 1.070904 / 0.031452 / 2.33 / 0.02 / 1.010959 / 1.134404
2.0 to 3.99 times poverty line / 1.23707 / 0.035775 / 7.36 / 0 / 1.168856 / 1.309264
4.00 or more times poverty line / 1.491868 / 0.044644 / 13.37 / 0 / 1.406827 / 1.58205
Private insurance / baseline
Public insurance only / 1.103886 / 0.030981 / 3.52 / 0 / 1.044764 / 1.166353
Uninsured / 0.350104 / 0.008401 / -43.74 / 0 / 0.334009 / 0.366975
Single / baseline
Married / 1.189043 / 0.029915 / 6.88 / 0 / 1.131793 / 1.249188
Widow/divorced/separated / 1.061738 / 0.032375 / 1.96 / 0.05 / 1.000102 / 1.127173
Region northeast / baseline
Region midwest / 0.86422 / 0.026444 / -4.77 / 0 / 0.813881 / 0.917672
Region south / 0.807961 / 0.02178 / -7.91 / 0 / 0.766352 / 0.851829
Region west / 0.783393 / 0.023245 / -8.23 / 0 / 0.739104 / 0.830336
Body Mass index / 1.00219 / 0.001546 / 1.42 / 0.156 / 0.999163 / 1.005226
Have hypertension / 2.444189 / 0.069501 / 31.43 / 0 / 2.311607 / 2.584374
Have high cholesterol / 2.817429 / 0.116438 / 25.06 / 0 / 2.598067 / 3.055311
Have diabetes / 2.19509 / 0.117871 / 14.64 / 0 / 1.975664 / 2.438886
Have IHD / 1.356208 / 0.190118 / 2.17 / 0.03 / 1.030195 / 1.785391
Have stroke / 1.182263 / 0.167862 / 1.18 / 0.238 / 0.894899 / 1.561904
Have colorectal cancer / 6.175258 / 2.218816 / 5.07 / 0 / 3.052108 / 12.49425
Have lung cancer / 14.89032 / 9.036673 / 4.45 / 0 / 4.528629 / 48.96
Have breast cancer / 6.640058 / 2.680911 / 4.69 / 0 / 3.007895 / 14.65822
Have other comorbidities / 4.771042 / 0.241054 / 30.93 / 0 / 4.320928 / 5.268044
Health status excellent / baseline
Health status very good / 1.2376 / 0.025489 / 10.35 / 0 / 1.188604 / 1.288616
Health status good / 1.544745 / 0.037415 / 17.95 / 0 / 1.473078 / 1.619898
Health status fair / 2.308003 / 0.089359 / 21.6 / 0 / 2.139231 / 2.490091
Health status poor / 3.702726 / 0.305978 / 15.84 / 0 / 3.148713 / 4.354217
Constant / 0.400444 / 0.035007 / -10.47 / 0 / 0.337348 / 0.475341
Number of outpatient visits
Number of strata = 419 / Number of obs = 190521Number of PSUs = 2098 / Population size = 1878632408
Design df = 1679
coefficient / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 0.077482 / 0.038298 / 2.02 / 0.043 / 0.002366 / 0.152598
Year 1999 / 0.088692 / 0.049028 / 1.81 / 0.071 / -0.00747 / 0.184855
Year 2000 / 0.028198 / 0.032904 / 0.86 / 0.392 / -0.03634 / 0.092736
Year 2001 / 0.067124 / 0.034273 / 1.96 / 0.05 / -9.9E-05 / 0.134346
Year 2002 / 0.122612 / 0.03485 / 3.52 / 0 / 0.054259 / 0.190965
Year 2003 / 0.122222 / 0.033575 / 3.64 / 0 / 0.056369 / 0.188075
Year 2004 / 0.12889 / 0.035642 / 3.62 / 0 / 0.058983 / 0.198797
Year 2005 / 0.125207 / 0.035326 / 3.54 / 0 / 0.05592 / 0.194495
Year 2006 / 0.080569 / 0.035573 / 2.26 / 0.024 / 0.010797 / 0.150341
Year 2007 / 0.057451 / 0.034863 / 1.65 / 0.1 / -0.01093 / 0.12583
Year 2008 / 0.041472 / 0.036505 / 1.14 / 0.256 / -0.03013 / 0.113072
Year 2009 / 0.040473 / 0.034729 / 1.17 / 0.244 / -0.02764 / 0.10859
Year 2010 / 0.027693 / 0.035982 / 0.77 / 0.442 / -0.04288 / 0.098266
Gender male / baseline
Gender female / 0.210755 / 0.009679 / 21.77 / 0 / 0.19177 / 0.229739
Age group 0-10 / baseline
Age group 11-20 / -0.07619 / 0.029556 / -2.58 / 0.01 / -0.13416 / -0.01822
Age group 21-30 / 0.020902 / 0.035377 / 0.59 / 0.555 / -0.04849 / 0.090289
Age group 31-40 / 0.127857 / 0.038014 / 3.36 / 0.001 / 0.053298 / 0.202416
Age group 41-50 / 0.166511 / 0.03737 / 4.46 / 0 / 0.093215 / 0.239807
Age group 51-60 / 0.277509 / 0.037566 / 7.39 / 0 / 0.203827 / 0.35119
Age group 61-70 / 0.378282 / 0.03783 / 10 / 0 / 0.304082 / 0.452482
Age group 71-80 / 0.514082 / 0.038235 / 13.45 / 0 / 0.43909 / 0.589074
Age group 81+ / 0.438861 / 0.040836 / 10.75 / 0 / 0.358766 / 0.518955
Race white non-Hispanic / baseline
Race white Hispanic / -0.23624 / 0.016167 / -14.61 / 0 / -0.26795 / -0.20453
Race Black / -0.24048 / 0.015757 / -15.26 / 0 / -0.27138 / -0.20957
Race Asian / -0.38743 / 0.023387 / -16.57 / 0 / -0.4333 / -0.34156
Race others / -0.05835 / 0.033066 / -1.76 / 0.078 / -0.1232 / 0.00651
No degree / baseline
High school or less / 0.055689 / 0.014032 / 3.97 / 0 / 0.028166 / 0.083212
Bachelor degree / 0.188349 / 0.016948 / 11.11 / 0 / 0.155107 / 0.22159
Master degree or more / 0.294913 / 0.021237 / 13.89 / 0 / 0.253259 / 0.336568
Below poverty line / baseline
1.01 to 1.24 times pov line / -0.00325 / 0.023119 / -0.14 / 0.888 / -0.04859 / 0.042099
1.25 to 1.99 times pov line / -0.02954 / 0.019326 / -1.53 / 0.127 / -0.06745 / 0.008363
2.0 to 3.99 times pov line / 0.010824 / 0.016707 / 0.65 / 0.517 / -0.02194 / 0.043592
4.00 or more times pov line / 0.089473 / 0.018077 / 4.95 / 0 / 0.054017 / 0.124929
Private insurance / baseline
Public insurance only / 0.058989 / 0.01427 / 4.13 / 0 / 0.031001 / 0.086977
Uninsured / -0.27155 / 0.019118 / -14.2 / 0 / -0.30904 / -0.23405
Single / baseline
Married / -0.06078 / 0.016182 / -3.76 / 0 / -0.09252 / -0.02904
Widow/divorced/separated / -0.0355 / 0.01923 / -1.85 / 0.065 / -0.07322 / 0.002215
Region northeast / baseline
Region midwest / -0.091 / 0.01682 / -5.41 / 0 / -0.12399 / -0.05801
Region south / -0.18044 / 0.017658 / -10.22 / 0 / -0.21508 / -0.14581
Region west / -0.07767 / 0.017796 / -4.36 / 0 / -0.11257 / -0.04276
Body Mass index / -0.0001 / 0.000801 / -0.13 / 0.897 / -0.00167 / 0.001466
Have hypertension / 0.076533 / 0.011588 / 6.6 / 0 / 0.053806 / 0.099261
Have high cholesterol / 0.109796 / 0.012081 / 9.09 / 0 / 0.0861 / 0.133492
Have diabetes / 0.114731 / 0.015439 / 7.43 / 0 / 0.084449 / 0.145013
Have IHD / 0.079931 / 0.032279 / 2.48 / 0.013 / 0.016619 / 0.143243
Have stroke / 0.183899 / 0.042611 / 4.32 / 0 / 0.100322 / 0.267476
Have colorectal cancer / 0.384268 / 0.065296 / 5.88 / 0 / 0.256197 / 0.512339
Have lung cancer / 0.504104 / 0.073908 / 6.82 / 0 / 0.359142 / 0.649065
Have breast cancer / 0.576956 / 0.03685 / 15.66 / 0 / 0.504679 / 0.649232
Have other comorbidities / 0.976098 / 0.02751 / 35.48 / 0 / 0.92214 / 1.030055
Health status excellent / baseline
Health status very good / 0.239167 / 0.013114 / 18.24 / 0 / 0.213446 / 0.264889
Health status good / 0.504121 / 0.014704 / 34.28 / 0 / 0.475281 / 0.532962
Health status fair / 0.88735 / 0.018425 / 48.16 / 0 / 0.851211 / 0.923489
Health status poor / 1.180883 / 0.026636 / 44.33 / 0 / 1.128639 / 1.233126
Constant / 0.115423 / 0.04689 / 2.46 / 0.014 / 0.023453 / 0.207393
Cost per outpatient visit
Number of strata = 419 / Number of obs = 190521Number of PSUs = 2098 / Population size = 1878632408
Design df = 1679
coefficient / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / -0.04431 / 0.053194 / -0.83 / 0.405 / -0.14865 / 0.060021
Year 1999 / 0.058151 / 0.065758 / 0.88 / 0.377 / -0.07082 / 0.187127
Year 2000 / 0.16883 / 0.076692 / 2.2 / 0.028 / 0.018409 / 0.319252
Year 2001 / 0.24784 / 0.075091 / 3.3 / 0.001 / 0.100558 / 0.395122
Year 2002 / 0.300684 / 0.074082 / 4.06 / 0 / 0.15538 / 0.445987
Year 2003 / 0.32983 / 0.078456 / 4.2 / 0 / 0.175949 / 0.483712
Year 2004 / 0.328643 / 0.074017 / 4.44 / 0 / 0.183469 / 0.473818
Year 2005 / 0.413033 / 0.077382 / 5.34 / 0 / 0.261258 / 0.564809
Year 2006 / 0.435854 / 0.075265 / 5.79 / 0 / 0.288232 / 0.583477
Year 2007 / 0.457459 / 0.075628 / 6.05 / 0 / 0.309124 / 0.605795
Year 2008 / 0.463093 / 0.074515 / 6.21 / 0 / 0.316941 / 0.609245
Year 2009 / 0.568807 / 0.075679 / 7.52 / 0 / 0.420372 / 0.717243
Year 2010 / 0.555318 / 0.079897 / 6.95 / 0 / 0.398611 / 0.712025
Gender male / baseline
Gender female / -0.09363 / 0.013786 / -6.79 / 0 / -0.12067 / -0.06659
Age group 0-10 / baseline
Age group 11-20 / 0.28593 / 0.064859 / 4.41 / 0 / 0.158718 / 0.413142
Age group 21-30 / 0.301524 / 0.079142 / 3.81 / 0 / 0.146296 / 0.456752
Age group 31-40 / 0.367052 / 0.080969 / 4.53 / 0 / 0.208242 / 0.525862
Age group 41-50 / 0.411108 / 0.080375 / 5.11 / 0 / 0.253463 / 0.568754
Age group 51-60 / 0.477192 / 0.080887 / 5.9 / 0 / 0.318542 / 0.635843
Age group 61-70 / 0.448043 / 0.080859 / 5.54 / 0 / 0.289448 / 0.606639
Age group 71-80 / 0.415129 / 0.079475 / 5.22 / 0 / 0.259249 / 0.57101
Age group 81+ / 0.339988 / 0.081314 / 4.18 / 0 / 0.180501 / 0.499475
Race white non-Hispanic / baseline
Race white Hispanic / 0.028352 / 0.023759 / 1.19 / 0.233 / -0.01825 / 0.074953
Race Black / 0.102224 / 0.028226 / 3.62 / 0 / 0.046861 / 0.157586
Race Asian / 0.049441 / 0.047438 / 1.04 / 0.297 / -0.0436 / 0.142485
Race others / 0.074005 / 0.052468 / 1.41 / 0.159 / -0.0289 / 0.176915
No degree / baseline
High school or less / 0.02192 / 0.018399 / 1.19 / 0.234 / -0.01417 / 0.058008
Bachelor degree / 0.005371 / 0.021781 / 0.25 / 0.805 / -0.03735 / 0.048092
Master degree or more / 0.012397 / 0.026909 / 0.46 / 0.645 / -0.04038 / 0.065175
Below poverty line / baseline
1.01 to 1.24 times pov line / -0.03543 / 0.031371 / -1.13 / 0.259 / -0.09696 / 0.026097
1.25 to 1.99 times pov line / 0.01404 / 0.029782 / 0.47 / 0.637 / -0.04437 / 0.072454
2.0 to 3.99 times pov line / 0.040828 / 0.026119 / 1.56 / 0.118 / -0.0104 / 0.092056
4.00 or more times pov line / 0.06335 / 0.028692 / 2.21 / 0.027 / 0.007074 / 0.119626
Private insurance / baseline
Public insurance only / -0.21018 / 0.018991 / -11.07 / 0 / -0.24743 / -0.17293
Uninsured / -0.25673 / 0.030082 / -8.53 / 0 / -0.31573 / -0.19773
Single / baseline
Married / 0.067018 / 0.022838 / 2.93 / 0.003 / 0.022224 / 0.111812
Widow/divorced/separated / 0.043792 / 0.024357 / 1.8 / 0.072 / -0.00398 / 0.091566
Region northeast / baseline
Region midwest / 0.12748 / 0.02242 / 5.69 / 0 / 0.083506 / 0.171454
Region south / 0.038381 / 0.019729 / 1.95 / 0.052 / -0.00031 / 0.077076
Region west / 0.06398 / 0.021848 / 2.93 / 0.003 / 0.021128 / 0.106833
Body Mass index / -0.00073 / 0.001197 / -0.61 / 0.542 / -0.00308 / 0.001618
Have hypertension / -0.03603 / 0.015417 / -2.34 / 0.02 / -0.06627 / -0.0058
Have high cholesterol / -0.03553 / 0.014254 / -2.49 / 0.013 / -0.06348 / -0.00757
Have diabetes / -0.05283 / 0.016728 / -3.16 / 0.002 / -0.08565 / -0.02002
Have IHD / 0.151293 / 0.049932 / 3.03 / 0.002 / 0.053358 / 0.249229
Have stroke / -0.01305 / 0.031512 / -0.41 / 0.679 / -0.07486 / 0.048756
Have colorectal cancer / 0.383024 / 0.060581 / 6.32 / 0 / 0.264201 / 0.501847
Have lung cancer / 0.51348 / 0.086336 / 5.95 / 0 / 0.344143 / 0.682818
Have breast cancer / 0.455117 / 0.053433 / 8.52 / 0 / 0.350314 / 0.559919
Have other comorbidities / 0.162372 / 0.047475 / 3.42 / 0.001 / 0.069255 / 0.255489
Number outpatient visits 0 / baseline
Number outpatient visits 1 / 0.020631 / 0.031869 / 0.65 / 0.517 / -0.04188 / 0.083139
Number outpatient visits 2 / 0.133332 / 0.028507 / 4.68 / 0 / 0.077419 / 0.189245
Number outp visits3-5 / 0.194463 / 0.028051 / 6.93 / 0 / 0.139443 / 0.249482
Number outp visits 6-10 / 0.124153 / 0.027053 / 4.59 / 0 / 0.071091 / 0.177214
Health status excellent / baseline
Health status very good / 0.007939 / 0.021941 / 0.36 / 0.718 / -0.0351 / 0.050973
Health status good / 0.06564 / 0.02268 / 2.89 / 0.004 / 0.021156 / 0.110123
Health status fair / 0.079929 / 0.026002 / 3.07 / 0.002 / 0.02893 / 0.130929
Health status poor / 0.119541 / 0.03116 / 3.84 / 0 / 0.058426 / 0.180657
Constant / 4.330302 / 0.079285 / 54.62 / 0 / 4.174795 / 4.48581
Probability of inpatient visits
Number of strata = 419 / Number of obs = 235582Number of PSUs = 2166 / Population size = 2243554589
Design df = 1747
F( 54, 1694) = 180.46
Prob > F = 0.0000
OR / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 1.03726 / 0.071123 / 0.53 / 0.594 / 0.906738 / 1.18657
Year 1999 / 0.982081 / 0.067298 / -0.26 / 0.792 / 0.858574 / 1.123355
Year 2000 / 1.219637 / 0.065939 / 3.67 / 0 / 1.09693 / 1.35607
Year 2001 / 1.393372 / 0.082384 / 5.61 / 0 / 1.240807 / 1.564695
Year 2002 / 1.316165 / 0.075507 / 4.79 / 0 / 1.176099 / 1.472912
Year 2003 / 1.290454 / 0.075986 / 4.33 / 0 / 1.149705 / 1.448434
Year 2004 / 1.330697 / 0.078493 / 4.84 / 0 / 1.185318 / 1.493907
Year 2005 / 1.30435 / 0.077015 / 4.5 / 0 / 1.161717 / 1.464494
Year 2006 / 1.284871 / 0.075295 / 4.28 / 0 / 1.145365 / 1.44137
Year 2007 / 1.221636 / 0.071567 / 3.42 / 0.001 / 1.089033 / 1.370385
Year 2008 / 1.188381 / 0.070292 / 2.92 / 0.004 / 1.058213 / 1.334561
Year 2009 / 1.153621 / 0.067615 / 2.44 / 0.015 / 1.028345 / 1.29416
Year 2010 / 1.122245 / 0.067748 / 1.91 / 0.056 / 0.996935 / 1.263307
Gender male / baseline
Gender female / 1.18297 / 0.017636 / 11.27 / 0 / 1.148882 / 1.218071
Age group 0-10 / baseline
Age group 11-20 / 1.013891 / 0.047199 / 0.3 / 0.767 / 0.925419 / 1.110821
Age group 21-30 / 1.083971 / 0.05581 / 1.57 / 0.118 / 0.979855 / 1.199149
Age group 31-40 / 0.756194 / 0.042756 / -4.94 / 0 / 0.676819 / 0.844878
Age group 41-50 / 0.553689 / 0.030734 / -10.65 / 0 / 0.496575 / 0.617373
Age group 51-60 / 0.49439 / 0.02805 / -12.42 / 0 / 0.442326 / 0.552582
Age group 61-70 / 0.525713 / 0.031189 / -10.84 / 0 / 0.467966 / 0.590587
Age group 71-80 / 0.624686 / 0.037031 / -7.94 / 0 / 0.556119 / 0.701706
Age group 81+ / 0.766137 / 0.04736 / -4.31 / 0 / 0.678659 / 0.864892
Race white non-Hispanic / baseline
Race white Hispanic / 0.885671 / 0.021832 / -4.93 / 0 / 0.843869 / 0.929543
Race Black / 1.205484 / 0.026068 / 8.64 / 0 / 1.155425 / 1.257712
Race Asian / 0.609898 / 0.025647 / -11.76 / 0 / 0.561615 / 0.662332
Race others / 1.07547 / 0.049403 / 1.58 / 0.113 / 0.982812 / 1.176863
No degree / baseline
High school or less / 0.914633 / 0.018412 / -4.43 / 0 / 0.879226 / 0.951466
Bachelor degree / 0.856816 / 0.021573 / -6.14 / 0 / 0.815532 / 0.90019
Master degree or more / 0.892535 / 0.031654 / -3.21 / 0.001 / 0.832561 / 0.95683
Below poverty line / baseline
1.01 to 1.24 times pov line / 0.859907 / 0.027467 / -4.73 / 0 / 0.807688 / 0.915503
1.25 to 1.99 times pov line / 0.839645 / 0.019539 / -7.51 / 0 / 0.802185 / 0.878854
2.0 to 3.99 times pov line / 0.725442 / 0.016251 / -14.33 / 0 / 0.694259 / 0.758026
4.00 or more times pov line / 0.669545 / 0.016551 / -16.23 / 0 / 0.637857 / 0.702807
Private insurance / baseline
Public insurance only / 1.20744 / 0.023672 / 9.62 / 0 / 1.161893 / 1.254772
Uninsured / 0.852962 / 0.021678 / -6.26 / 0 / 0.811486 / 0.896557
Single / baseline
Married / 1.250883 / 0.029605 / 9.46 / 0 / 1.194145 / 1.310317
Widow/divorced/separated / 1.305007 / 0.03539 / 9.82 / 0 / 1.237409 / 1.376297
Region northeast / baseline
Region midwest / 1.018115 / 0.024142 / 0.76 / 0.449 / 0.971849 / 1.066584
Region south / 0.958394 / 0.020675 / -1.97 / 0.049 / 0.91869 / 0.999814
Region west / 0.827083 / 0.020371 / -7.71 / 0 / 0.788078 / 0.868019
Body Mass index / 1.003819 / 0.001147 / 3.34 / 0.001 / 1.001572 / 1.006071
Have hypertension / 1.148198 / 0.02376 / 6.68 / 0 / 1.102531 / 1.195757
Have high cholesterol / 0.9426 / 0.019858 / -2.81 / 0.005 / 0.904446 / 0.982363
Have diabetes / 1.183537 / 0.028864 / 6.91 / 0 / 1.128257 / 1.241525
Have IHD / 2.74116 / 0.160204 / 17.25 / 0 / 2.444288 / 3.074088
Have stroke / 2.159589 / 0.124727 / 13.33 / 0 / 1.928306 / 2.418612
Have colorectal cancer / 2.377966 / 0.278143 / 7.41 / 0 / 1.89049 / 2.991142
Have lung cancer / 2.430296 / 0.324856 / 6.64 / 0 / 1.869825 / 3.158766
Have breast cancer / 1.413833 / 0.11652 / 4.2 / 0 / 1.202814 / 1.661874
Have other comorbidities / 6.487379 / 0.50851 / 23.85 / 0 / 5.56291 / 7.56548
Health status excellent / baseline
Health status very good / 1.295599 / 0.027318 / 12.28 / 0 / 1.243112 / 1.350302
Health status good / 1.898477 / 0.044212 / 27.53 / 0 / 1.813714 / 1.987201
Health status fair / 3.133632 / 0.087241 / 41.03 / 0 / 2.967112 / 3.309497
Health status poor / 4.960536 / 0.19654 / 40.42 / 0 / 4.589654 / 5.361388
Constant / 0.024069 / 0.002444 / -36.7 / 0 / 0.019723 / 0.029374
Number of inpatient visits
Number of strata = 412 / Number of obs = 51413Number of PSUs = 1724 / Population size = 460894547
Design df = 1312
coefficient / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / 0.020813 / 0.038177 / 0.55 / 0.586 / -0.05408 / 0.095709
Year 1999 / -0.01567 / 0.031514 / -0.5 / 0.619 / -0.0775 / 0.046152
Year 2000 / 0.043868 / 0.028338 / 1.55 / 0.122 / -0.01173 / 0.099461
Year 2001 / 0.082895 / 0.030386 / 2.73 / 0.006 / 0.023285 / 0.142505
Year 2002 / 0.076013 / 0.030147 / 2.52 / 0.012 / 0.016871 / 0.135154
Year 2003 / 0.072349 / 0.030587 / 2.37 / 0.018 / 0.012345 / 0.132352
Year 2004 / 0.083798 / 0.031005 / 2.7 / 0.007 / 0.022973 / 0.144624
Year 2005 / 0.069685 / 0.031643 / 2.2 / 0.028 / 0.007609 / 0.13176
Year 2006 / 0.079154 / 0.031267 / 2.53 / 0.011 / 0.017815 / 0.140493
Year 2007 / 0.072875 / 0.031363 / 2.32 / 0.02 / 0.011349 / 0.134402
Year 2008 / 0.06025 / 0.031488 / 1.91 / 0.056 / -0.00152 / 0.122022
Year 2009 / 0.020085 / 0.030758 / 0.65 / 0.514 / -0.04026 / 0.080426
Year 2010 / 0.045229 / 0.031682 / 1.43 / 0.154 / -0.01692 / 0.107382
Gender male / baseline
Gender female / 0.004336 / 0.008701 / 0.5 / 0.618 / -0.01273 / 0.021406
Age group 0-10 / baseline
Age group 11-20 / -0.0342 / 0.020876 / -1.64 / 0.102 / -0.07515 / 0.006756
Age group 21-30 / -0.02462 / 0.025779 / -0.96 / 0.34 / -0.0752 / 0.025948
Age group 31-40 / -0.0397 / 0.026697 / -1.49 / 0.137 / -0.09207 / 0.012676
Age group 41-50 / -0.05951 / 0.026275 / -2.26 / 0.024 / -0.11105 / -0.00796
Age group 51-60 / -0.04763 / 0.028005 / -1.7 / 0.089 / -0.10257 / 0.007308
Age group 61-70 / -0.02117 / 0.028351 / -0.75 / 0.455 / -0.07679 / 0.034444
Age group 71-80 / 0.012597 / 0.029029 / 0.43 / 0.664 / -0.04435 / 0.069545
Age group 81+ / 0.053806 / 0.031143 / 1.73 / 0.084 / -0.00729 / 0.114901
Race white non-Hispanic / baseline
Race white Hispanic / -0.0642 / 0.013168 / -4.88 / 0 / -0.09003 / -0.03836
Race Black / -0.01919 / 0.012473 / -1.54 / 0.124 / -0.04366 / 0.005274
Race Asian / -0.0784 / 0.022438 / -3.49 / 0 / -0.12242 / -0.03439
Race others / -0.02838 / 0.02434 / -1.17 / 0.244 / -0.07613 / 0.01937
No degree / baseline
High school or less / 0.020989 / 0.010943 / 1.92 / 0.055 / -0.00048 / 0.042457
Bachelor degree / 0.004419 / 0.014299 / 0.31 / 0.757 / -0.02363 / 0.032471
Master degree or more / 0.01943 / 0.023505 / 0.83 / 0.409 / -0.02668 / 0.065541
Below poverty line / baseline
1.01 to 1.24 times pov line / -0.02967 / 0.019853 / -1.49 / 0.135 / -0.06861 / 0.009282
1.25 to 1.99 times pov line / -0.03753 / 0.014257 / -2.63 / 0.009 / -0.0655 / -0.00957
2.0 to 3.99 times pov line / -0.06416 / 0.013938 / -4.6 / 0 / -0.09151 / -0.03682
4.00 or more times pov line / -0.06511 / 0.015282 / -4.26 / 0 / -0.09509 / -0.03512
Private insurance / baseline
Public insurance only / 0.063389 / 0.012771 / 4.96 / 0 / 0.038334 / 0.088443
Uninsured / -0.0211 / 0.013527 / -1.56 / 0.119 / -0.04764 / 0.005435
Single / baseline
Married / -0.02997 / 0.013568 / -2.21 / 0.027 / -0.05659 / -0.00335
Widow/divorced/separated / 0.008518 / 0.01538 / 0.55 / 0.58 / -0.02165 / 0.03869
Region northeast / baseline
Region midwest / 0.023248 / 0.012944 / 1.8 / 0.073 / -0.00215 / 0.048642
Region south / 0.010819 / 0.012516 / 0.86 / 0.387 / -0.01373 / 0.035372
Region west / -0.00182 / 0.013532 / -0.13 / 0.893 / -0.02837 / 0.024728
Body Mass index / -0.00026 / 0.000703 / -0.38 / 0.707 / -0.00164 / 0.001115
Have hypertension / 0.048889 / 0.012676 / 3.86 / 0 / 0.024022 / 0.073756
Have high cholesterol / 0.003309 / 0.012549 / 0.26 / 0.792 / -0.02131 / 0.027926
Have diabetes / 0.045927 / 0.015392 / 2.98 / 0.003 / 0.015732 / 0.076122
Have IHD / 0.204603 / 0.02563 / 7.98 / 0 / 0.154324 / 0.254883
Have stroke / 0.17393 / 0.028634 / 6.07 / 0 / 0.117757 / 0.230103
Have colorectal cancer / 0.052936 / 0.054966 / 0.96 / 0.336 / -0.0549 / 0.160767
Have lung cancer / 0.088868 / 0.052274 / 1.7 / 0.089 / -0.01368 / 0.191418
Have breast cancer / -0.08344 / 0.040218 / -2.07 / 0.038 / -0.16234 / -0.00454
Have other comorbidities / 0.064545 / 0.034377 / 1.88 / 0.061 / -0.00289 / 0.131984
Health status excellent / baseline
Health status very good / 0.081007 / 0.011639 / 6.96 / 0 / 0.058175 / 0.103839
Health status good / 0.187782 / 0.012161 / 15.44 / 0 / 0.163925 / 0.211639
Health status fair / 0.406789 / 0.016909 / 24.06 / 0 / 0.373617 / 0.43996
Health status poor / 0.598323 / 0.023771 / 25.17 / 0 / 0.55169 / 0.644956
Constant / 0.196394 / 0.04799 / 4.09 / 0 / 0.102248 / 0.29054
Cost per inpatient visit
Number of strata = 412 / Number of obs = 51413Number of PSUs = 1724 / Population size = 460894547
Design df = 1312
coefficient / Std err / t / P>t / CI [lb] / CI [ub]
Year 1997 / baseline
Year 1998 / -0.11336 / 0.070512 / -1.61 / 0.108 / -0.25168 / 0.024973
Year 1999 / 0.156481 / 0.105065 / 1.49 / 0.137 / -0.04963 / 0.362594
Year 2000 / 0.051944 / 0.075121 / 0.69 / 0.489 / -0.09543 / 0.199315
Year 2001 / 0.072444 / 0.077237 / 0.94 / 0.348 / -0.07908 / 0.223965
Year 2002 / 0.136147 / 0.077678 / 1.75 / 0.08 / -0.01624 / 0.288533
Year 2003 / 0.183299 / 0.078296 / 2.34 / 0.019 / 0.029699 / 0.336898
Year 2004 / 0.25162 / 0.082101 / 3.06 / 0.002 / 0.090556 / 0.412684
Year 2005 / 0.21211 / 0.078724 / 2.69 / 0.007 / 0.05767 / 0.366549
Year 2006 / 0.233146 / 0.078986 / 2.95 / 0.003 / 0.078193 / 0.388098
Year 2007 / 0.308104 / 0.078403 / 3.93 / 0 / 0.154295 / 0.461913
Year 2008 / 0.310979 / 0.080448 / 3.87 / 0 / 0.153159 / 0.468799
Year 2009 / 0.425484 / 0.079409 / 5.36 / 0 / 0.269702 / 0.581266
Year 2010 / 0.4004 / 0.081321 / 4.92 / 0 / 0.240867 / 0.559934
Gender male / baseline
Gender female / -0.08085 / 0.018042 / -4.48 / 0 / -0.11625 / -0.04546
Age group 0-10 / baseline
Age group 11-20 / 0.224508 / 0.089008 / 2.52 / 0.012 / 0.049896 / 0.399121
Age group 21-30 / 0.21094 / 0.095054 / 2.22 / 0.027 / 0.024465 / 0.397415
Age group 31-40 / 0.210935 / 0.095416 / 2.21 / 0.027 / 0.023749 / 0.39812
Age group 41-50 / 0.35043 / 0.096877 / 3.62 / 0 / 0.160379 / 0.540482
Age group 51-60 / 0.424197 / 0.094539 / 4.49 / 0 / 0.238733 / 0.609661
Age group 61-70 / 0.451483 / 0.098409 / 4.59 / 0 / 0.258426 / 0.64454
Age group 71-80 / 0.354683 / 0.097732 / 3.63 / 0 / 0.162954 / 0.546411
Age group 81+ / 0.312005 / 0.097345 / 3.21 / 0.001 / 0.121037 / 0.502973
Race white non-Hispanic / baseline
Race white Hispanic / 0.064744 / 0.024969 / 2.59 / 0.01 / 0.015761 / 0.113727
Race Black / -0.02489 / 0.022746 / -1.09 / 0.274 / -0.06951 / 0.019733
Race Asian / 0.06755 / 0.05565 / 1.21 / 0.225 / -0.04162 / 0.176724
Race others / 0.033395 / 0.050146 / 0.67 / 0.506 / -0.06498 / 0.131771
No degree / baseline
High school or less / 0.027202 / 0.026503 / 1.03 / 0.305 / -0.02479 / 0.079194
Bachelor degree / 0.084801 / 0.033561 / 2.53 / 0.012 / 0.018963 / 0.15064
Master degree or more / 0.060941 / 0.040196 / 1.52 / 0.13 / -0.01791 / 0.139797
Below poverty line / baseline
1.01 to 1.24 times pov line / 0.042035 / 0.032365 / 1.3 / 0.194 / -0.02146 / 0.105528
1.25 to 1.99 times pov line / 0.16249 / 0.029737 / 5.46 / 0 / 0.104154 / 0.220826
2.0 to 3.99 times pov line / 0.182002 / 0.025176 / 7.23 / 0 / 0.132613 / 0.231391
4.00 or more times pov line / 0.264539 / 0.0305 / 8.67 / 0 / 0.204705 / 0.324374
Private insurance / baseline
Public insurance only / -0.2487 / 0.022396 / -11.1 / 0 / -0.29264 / -0.20477
Uninsured / -0.30775 / 0.036792 / -8.36 / 0 / -0.37993 / -0.23558
Single / baseline
Married / -0.00888 / 0.024743 / -0.36 / 0.72 / -0.05742 / 0.039657
Widow/divorced/separated / -0.01625 / 0.029111 / -0.56 / 0.577 / -0.07336 / 0.040862
Region northeast / baseline
Region midwest / 0.113113 / 0.024565 / 4.6 / 0 / 0.064921 / 0.161304
Region south / -0.01206 / 0.024198 / -0.5 / 0.618 / -0.05953 / 0.035408
Region west / 0.144831 / 0.025926 / 5.59 / 0 / 0.093971 / 0.195692
Body Mass index / -0.00348 / 0.001297 / -2.68 / 0.007 / -0.00602 / -0.00093
Have hypertension / 0.005723 / 0.020831 / 0.27 / 0.784 / -0.03514 / 0.046588
Have high cholesterol / 0.035351 / 0.0234 / 1.51 / 0.131 / -0.01055 / 0.081257
Have diabetes / -0.03546 / 0.023739 / -1.49 / 0.135 / -0.08203 / 0.011109
Have IHD / 0.220488 / 0.046275 / 4.76 / 0 / 0.129707 / 0.31127
Have stroke / 0.057535 / 0.033883 / 1.7 / 0.09 / -0.00893 / 0.124005
Have colorectal cancer / -0.02897 / 0.056381 / -0.51 / 0.607 / -0.13958 / 0.081635
Have lung cancer / -0.13421 / 0.067543 / -1.99 / 0.047 / -0.26671 / -0.0017
Have breast cancer / -0.14481 / 0.057461 / -2.52 / 0.012 / -0.25754 / -0.03209
Have other comorbidities / -0.16744 / 0.08577 / -1.95 / 0.051 / -0.3357 / 0.000817
Number inpatient stays 1 / baseline
Number inpatient stays 2 / -0.04037 / 0.023644 / -1.71 / 0.088 / -0.08675 / 0.006015
Number inpatient stays 3+ / -0.15116 / 0.025401 / -5.95 / 0 / -0.20099 / -0.10133
Had surgery / 0.618391 / 0.017067 / 36.23 / 0 / 0.584909 / 0.651873
Had access from ER / -0.70587 / 0.024922 / -28.32 / 0 / -0.75476 / -0.65698
Nights in hospital 0 / baseline
Nights in hospital 1 / 1.040335 / 0.029045 / 35.82 / 0 / 0.983354 / 1.097315
Nights in hospital 2 / 1.294323 / 0.024686 / 52.43 / 0 / 1.245894 / 1.342752
Nights in hospital 3-4 / 1.496587 / 0.024909 / 60.08 / 0 / 1.447722 / 1.545453
Nights in hospital 5-7 / 1.855211 / 0.030744 / 60.34 / 0 / 1.794899 / 1.915524
Nights in hospital 7+ / 2.428363 / 0.040297 / 60.26 / 0 / 2.34931 / 2.507416
Health status excellent / baseline
Health status very good / 0.026184 / 0.030625 / 0.85 / 0.393 / -0.0339 / 0.086263
Health status good / 0.009121 / 0.030566 / 0.3 / 0.765 / -0.05084 / 0.069084
Health status fair / 0.065813 / 0.034942 / 1.88 / 0.06 / -0.00274 / 0.134361
Health status poor / 0.063721 / 0.042519 / 1.5 / 0.134 / -0.01969 / 0.147134
Constant / 7.0956 / 0.112225 / 63.23 / 0 / 6.87544 / 7.315761