Table 3.
Multivariable logistic regression model of prehospital characteristics associated with hospital admission among all EMS encounters with respiratory distress*
| Variable | Adjusted Odds Ratio |
95% CI | P value |
|---|---|---|---|
| Age, by 5 years | 1.14 | 1.13–1.15 | <0.0001 |
| Male sex | 1.17 | 1.09–1.25 | <0.0001 |
| Vital signs | |||
| Respiratory rate, by 5 breaths per min | 1.29 | 1.24–1.35 | <0.0001 |
| Pulse oximetry, by 10% | 0.81 | 0.75–0.88 | <0.0001 |
| Systolic blood pressure, by 10 mmHg | 0.98 | 0.97–0.99 | <0.0001 |
| Heart rate, by 10 beats per min | 1.09 | 1.07–1.11 | <0.0001 |
| Glasgow Coma Scale score | 0.97 | 0.94–0.99 | 0.02 |
| EMS provider impression | |||
| Shortness of breath | 1.21 | 1.10–1.33 | <0.0001 |
| Asthma | 0.75 | 0.64–0.88 | <0.0001 |
| COPD / emphysema | 1.26 | 1.08–1.47 | 0.003 |
| Respiratory depression | 1.50 | 1.24–1.82 | <0.0001 |
| Other | Ref | . | . |
| EMS severity code^ | |||
| ALS patients | |||
| Life-threatening | 3.24 | 2.71–3.86 | <0.0001 |
| Urgent | 2.13 | 1.92–2.36 | <0.0001 |
| Non-urgent | 1.29 | 1.16–1.43 | <0.0001 |
| BLS patients | |||
| Life-threatening | 1.54 | 0.998–2.38 | 0.05 |
| Urgent | 1.31 | 1.18–1.45 | <0.0001 |
| Non-urgent | Ref | . | . |
| Incident location | |||
| Routine / home | 2.19 | 1.83–2.61 | <0.0001 |
| Nursing home | 2.80 | 2.28–3.43 | <0.0001 |
| Public building | 1.04 | 0.79–1.37 | 0.76 |
| Street / highway | 0.74 | 0.52–1.04 | 0.09 |
| Adult family home | 2.12 | 1.65–2.73 | <0.0001 |
| Medical facility | 2.75 | 2.16–3.51 | <0.0001 |
*
Model uses robust variance estimates, and includes the year in cohort, the responding EMS agency, and receiving hospital as fixed effects (not shown). Total observations with complete data were 17,156.
^
Likelihood ratio test for multiplicative interaction term (ALS x EMS severity code) p<0.01. Referent category for all EMS severity code terms is BLS x non-urgent.
COPD = chronic obstructive pulmonary disease