Table 2.
Logistic regression variable parameters
| Parametera,b | Description | Estimatec | Odds ratio (95% confidence interval) |
|---|---|---|---|
| Intercept | 0.4063 | ||
| Age (years) | 40 ≤ Age < 56 | − 0.9741 | 0.38 (0.36, 0.4) |
| 67 ≤ Age < 77 | 0.7216 | 2.06 (1.94, 2.19) | |
| Age ≥ 77 | 1.5844 | 4.88 (4.54, 5.23) | |
| Heart disease (derived) | Present | 0.5053 | 1.66 (1.55, 1.77) |
| Albumin (g/dL) | Albumin < 3.5 | 0.7438 | 2.1 (1.93, 2.3) |
| BMI (kg/m2) | Missing | 0.0884 | 1.09 (0.99, 1.21) |
| BMI < 18.5 | 0.6086 | 1.84 (1.26, 2.69) | |
| 24.9 ≤ BMI ≤ 29.9 | 0.0384 | 1.04 (0.92, 1.17) | |
| BMI > 29.9 | 0.3723 | 1.45 (1.3, 1.62) | |
| COPD diagnosis | Present | 0.5259 | 1.69 (1.57, 1.82) |
| Gender | Female | − 0.6226 | 0.54 (0.51, 0.56) |
| Heart failure diagnosis | Present | 1.0609 | 2.89 (2.53, 3.31) |
| Insurance | Commercial | − 0.4111 | 0.66 (0.62, 0.71) |
| Medicaid | 0.0378 | 1.04 (0.95, 1.13) | |
| Other/unknown | − 0.8584 | 0.42 (0.39, 0.46) | |
| Kidney disease (derived) | Present | 0.58 | 1.79 (1.59, 2.01) |
| Shock diagnosis | Present | 0.6219 | 1.86 (1.67, 2.08) |
aSee Additional file 1, for codes and logic used for extraction and derivation of parameters
bReference parameters: Age 56–66 years (inclusive), no calculated heart disease, albumin ≥ 3.5 (or missing value), normal BMI (19.5–24.9), no COPD, male, no heart failure, Medicare insurance, no calculated kidney disease, and no shock.
cEach eligible patient had a risk score of exp(raw score)/(1 + exp(raw score)), where the raw score was the sum of the intercept and parameter estimates corresponding to the patients characteristics in each parameter.