Binary Logistic Regression Model of factors predictive of death at 120 days from the point of diagnosis of pneumomediastinum (all patients eligible for mechanical ventilation, n=315)
| B(se) | Odds Ratio or % increase per unit (95% CI) | p | |
| Mechanically ventilated (at diagnosis) | 1.40 (0.26) | 4.0 (2.4–6.7) | <0.001 |
| Age | −0.38 (0.12) | 3.7% per year (1.4–5.9) | <0.01 |
| Diabetes mellitus | 0.59 (0.34) | 1.8 (0.9–3.5) | 0.08 |
All variables significantly associated with mortality in univariate analyses were entered into the model stepwise, backwards. The model produces prediction accuracy for outcome of 68.4% versus a 51.1% default accuracy.
Model R2=0.251 Nagelkerke χ2 (6)=65.2 p<0.001. Constant B(se)=2.38 (0.79) Variables in the regression but not listed, subcutaneous emphysema (p=0.12), Hypertension (p=0.35), ischaemic heart disease/left ventricular systolic dysfunction (p=0.50).