Table 3.
Instrumental variables model predicting hospital mortality, using an instrument of distance to a top-decile sepsis volume hospital. The naïve model is the linear regression model without using the instrumental variables approach.
| Naïve Model (Ordinary Least Squares) |
Instrumental Variable: 2-Stage Least Squares* (Linear) |
|||
|---|---|---|---|---|
| Factor | aOR (95%CI) | p | β (95%CI) | p |
| Rural Hospital Bypass | 0.061 (0.032 – 0.090) |
< 0.001 | 0.056 (0.022 – 0.089) |
0.001 |
| Inter-hospital Transfer | 0.097 (0.082 – 0.112) |
< 0.001 | 0.075 (0.005 – 0.144) |
0.034 |
| Age, per decade increase |
0.023 (0.018 – 0.029) |
< 0.001 | 0.022 (0.013 – 0.030) |
< 0.001 |
| Non-White | 0.018 (−0.036 – 0.071) |
0.523 | 0.018 (−0.035 – 0.072) |
0.503 |
| Male | −0.019 (−0.032) – −0.006) |
0.004 | −0.019 (−0.032 – − 0.006) |
0.004 |
| Rural Residence31 | 0.021 (−0.002 – 0.045) |
0.073 | 0.020 (−0.003 – 0.044) |
0.094 |
| Insurance Type | 0.101 | |||
| Medicare | 0.014 (−0.009 – 0.037) |
0.100 | 0.012 (−0.012 – 0.036) |
|
| Medicaid | 0.024 (−0.009 – 0.057) |
0.023 (−0.012 – 0.036) |
||
| Commercial | 0 (ref) | 0 (ref) | ||
| Uninsured | 0.050 (0.008 – 0.091) |
0.051 (0.009 – 0.093) |
||
| Source of Infection28 | ||||
| Pneumonia | −0.044 (−0.059 – −0.029) |
< 0.001 | −0.048 (−0.068 – − 0.028) |
< 0.001 |
| Urinary Tract Infection |
−0.118 (−0.135 – −0.101) |
< 0.001 | −0.123 (−0.144 –− 0.101) |
< 0.001 |
| Cellulitis and Soft Tissue Infection |
−0.110 (−0.136 – −0.084) |
< 0.001 | −0.113 (−0.140 – − 0.085) |
<0.001 |
| Comorbidities (Elixhauser methodology)30 |
||||
| Congestive Heart Failure |
0.032 (0.017 – 0.047) |
< 0.001 | 0.033 (0.018 – 0.049) |
< 0.001 |
| Valvular Heart Disease |
−0.007 (−0.033 – 0.018) |
0.571 | −0.005 (−0.031 – 0.022) |
0.727 |
| Peripheral Vascular Disease | 0.039 (0.017 – 0.061) |
< 0.001 | 0.042 (0.018 – 0.066) |
< 0.001 |
| Hypertension | −0.051 (−0.064 – −0.037) |
< 0.001 | −0.048 (−0.063 – − 0.033) |
< 0.001 |
| Neurologic Disorders | 0.019 (0.001 – 0.038) |
0.045 | 0.019 (−0.001 – 0.038) |
0.052 |
| Chronic Pulmonary Disease |
0.004 (−0.010 – 0.019) |
0.565 | 0.007 (−0.010 – 0.024) |
0.407 |
| Diabetes Mellitus with Complications |
−0.032 (−0.047 – −0.016) |
< 0.001 | −0.031 (−0.47 – −0.015) |
<0.001 |
| Renal Failure | −0.015 (−0.030 – 0.001) |
0.054 | −0.013 (−0.029 – 0.003) |
0.119 |
| Liver Disease | 0.091 (0.060 – 0.123) |
< 0.001 | 0.093 (0.061 – 0.124) |
<0.001 |
| Metastatic Cancer | 0.102 (0.067 – 0.138) |
< 0.001 | 0.105 (0.068 – 0.141) |
< 0.001 |
95% CI, 95% confidence interval
*
Instrumental variables model F-statistic = 623.5.
**
All numbered references in this table refer to reference numbers from the main manuscript.