Table 5 Incremental linear robust models highlighting potential omitted variable bias
(1) Basic model (Omitted variable bias) | (2) Basic model | (3) Extended model | (4) Model incl. patient confounding | (5) Model incl. all confounders | |
|---|---|---|---|---|---|
Constant | 0.095∗∗∗ | 0.084∗∗∗ | 0.563∗∗∗ | 0.647∗∗∗ | 0.675∗∗∗ |
(0.008) | (0.008) | (0.011) | (0.024) | (0.049) | |
Basic model weekends | |||||
Admission WE | −0.053∗ | −0.063∗ | −0.066∗∗ | −0.064∗∗ | −0.041· |
(0.025) | (0.025) | (0.021) | (0.021) | (0.021) | |
Scanning WE | −0.147∗∗∗ | 0.011 | 0.061∗∗ | 0.061∗∗ | 0.051∗ |
(0.032) | (0.028) | (0.023) | (0.023) | (0.023) | |
Discharge WE | 0.160∗∗∗ | 0.167∗∗∗ | 0.035∗ | 0.033· | 0.015 |
(0.020) | (0.021) | (0.017) | (0.017) | (0.017) | |
Treatment WE | −0.104∗∗ | 0.149∗∗∗ | 0.086∗∗∗ | 0.087∗∗∗ | 0.079∗∗∗ |
(0.038) | (0.028) | (0.023) | (0.023) | (0.023) | |
Interaction WE scan and treatment | 0.536∗∗∗ | ||||
(0.054) | |||||
Number of exams | -0.005 | −0.005· | 0.001 | ||
(0.003) | (0.003) | (0.003) | |||
Diff. scan and admission (in days) | −0.048∗∗∗ | −0.048∗∗∗ | −0.049∗∗∗ | ||
(0.002) | (0.002) | (0.002) | |||
Diff. treatment and scan (in days) | 0.004∗ | 0.004∗ | 0.003· | ||
(0.002) | (0.002) | (0.002) | |||
Diff. dismissal and scan (in days) | −0.041∗∗∗ | −0.041∗∗∗ | −0.039∗∗∗ | ||
(0.001) | (0.001) | (0.001) | |||
Patient data | |||||
Female | −0.075∗∗∗ | −0.080∗∗∗ | |||
(0.012) | (0.011) | ||||
Age | −0.001∗ | −0.001∗ | |||
(0.000) | (0.000) | ||||
Private insurance | −0.012 | −0.007 | |||
(0.013) | (0.013) | ||||
Clinical data | |||||
Deceased | 0.464∗∗∗ | ||||
(0.032) | |||||
Emergency | −0.132∗∗∗ | ||||
(0.013) | |||||
Internal medicine case | 0.113∗∗∗ | ||||
(0.034) | |||||
Surgical case | −0.065· | ||||
(0.033) | |||||
MRI | 0.115∗∗∗ | ||||
(0.032) | |||||
CT | 0.082∗∗ | ||||
(0.030) | |||||
X-ray | 0.091∗∗ | ||||
(0.030) | |||||
Complicated radiology case | −0.104∗∗∗ | ||||
(0.020) | |||||
Adj. R2 | 0.017 | 0.009 | 0.323 | 0.326 | 0.355 |
Num. obs. | 11371 | 11371 | 11371 | 11371 | 11371 |