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Table 2 Stepwise variable selection on dataset B

From: Predicting emergency department visits in a large teaching hospital

Variable Estimate Standard error t-value P-value Significance level
(Intercept) 248.911211 46.168830 5.391 9.01e−08 <.001
Monday 11.186836 1.049152 10.663 <2e−16 <.001
Friday 9.124763 1.405000 6.494 1.40e−10 <.001
Saturday − 8.856937 1.151790 − 7.690 3.98e−14 <.001
Sunday − 9.348118 1.858019 − 5.031 5.92e−07 <.001
May − 2.833858 1.505424 − 1.882 0.060110 N.S.
August − 2.783141 1.467921 − 1.896 0.058294 N.S.
Friday * Spring 6.425346 2.359589 2.723 0.006597 <.01
Wednesday * Summer − 2.758180 1.800220 − 1.523 0.125852 N.S.
Friday * Summer − 4.491005 2.170668 − 2.069 0.038845 <.05
Tuesday * Fall − 4.747532 1.754273 − 2.706 0.006937 <.01
Thursday * Fall − 4.330716 1.751428 − 2.473 0.013600 <.05
Saturday * Winter − 4.727871 2.171958 − 2.177 0.029765 <.05
Summer vacation week 1 + 2 − 7.220153 1.869252 − 3.863 0.000120 <.001
Summer vacation week 3 + 4 − 9.962722 1.862460 − 5.349 1.13e−07 <.001
Friday * Vacation − 6.502580 2.961668 − 2.196 0.028385 <.05
Monday * Holiday − 23.301127 3.296739 − 7.068 3.22e−12 <.001
Wednesday * Holiday − 23.211391 6.806075 − 3.410 0.000682 <.001
Thursday * Holiday − 25.870551 5.598786 − 4.621 4.40e−06 <.001
Friday * Holiday − 26.937684 9.743801 − 2.765 0.005820 <.01
Time trend 0.010184 0.001397 7.292 6.87e−13 <.001
Sunday * Time trend − 0.006243 0.003389 − 1.842 0.065813 N.S.
Summer vacation * time trend − 0.013159 0.002659 − 4.948 8.99e−07 <.001
Carnival * Time trend 0.026781 0.008749 3.061 0.002274 <.01
Summer * Minimum wind speed Kaathoven 1.227642 0.422316 2.907 0.003742 <.01
Summer * Minimum wind speed Drunen − 1.104485 0.439693 − 2.512 0.012186 <.05
Maximum temperature Drunen 0.033942 0.009225 3.680 0.000248 <.001
Winter * Maximum temperature Kaathoven − 0.072152 0.023500 − 3.070 0.002205 <.01
Radiation Drunen 0.003902 0.001086 3.592 0.000347 <.001
Maximum pressure Kaathoven − 0.014939 0.004470 − 3.342 0.000866 <.001
Maximum humidity Drunen − 0.244718 0.099745 − 2.453 0.014345 <.05
Winter * Mean humidity Kaathoven 1.056103 0.460616 2.293 0.022096 <.05
Winter * Mean humidity Drunen − 0.942567 0.465086 − 2.072 0.043002 <.05
Cloudiness Kaathoven 4.299755 1.479477 2.906 0.003750 <.01
Cloudiness Drunen − 3.950170 1.452272 − 2.720 0.006658 <.01
Minimum visibility Kaathoven − 0.028843 0.011739 − 2.457 0.014203 <.05
Fall * Minimum visibility Drunen 0.060823 0.016224 3.749 0.000189 <.001
Fall * Maximum visibility Drunen − 0.011680 0.004764 − 2.451 0.014422 <.05
Precipitation duration Kaathoven − 0.229262 0.101833 − 2.939 0.003382 <.01
Precipitation duration Drunen 0.349550 0.102416 3.413 0.000672 <.001
Summer * Precipitation Kaathoven (precipitation stations) − 0.040857 0.023192 − 1.762 0.078436 N.S.
Summer * Precipitation Duration Drunen − 0.127771 0.043480 − 2.939 0.003384 <.01
Summer vacation * Precipitation Kaathoven (precipitation stations) 0.138976 0.046988 2.958 0.003183 <.01
Summer vacation * Maximum Precipitation Drunen − 0.105203 0.046440 − 2.265 0.023736 <.05
Hours of fog 1.254639 0.292019 4.296 1.93e−05 <.001
Spring * Hours of fog Drunen − 0.708256 0.492974 − 1.437 0.151162 N.S.
Winter * Hours of fog Kaathoven − 2.742514 0.928981 − 2.952 0.003240 <.01
Winter * Hours of fog Drunen 1.726884 0.951881 1.814 0.069993 N.S.
Winter * Hours of snow − 1.150906 0.375299 − 3.067 0.002232 <.01
Residual standard error 9.439 on 872 degrees of freedom
Multiple R-squared 0.5587
Adjusted R-squared 0.5344
F-statistic 23 on 48 and 872 degrees of freedom, P-value: < 2.2e−16
  1. Dataset B is based on calendar variables plus weather predictions at Kaathoven and Drunen; * = interaction; N.S. not significant