Table 4. Multivariable proportional hazards regression models of 1-y mortality.
| Variable | Model 1 | Model 2 | ||||
|---|---|---|---|---|---|---|
| aHR | 95% CI | p-Value | aHR | 95% CI | p-Value* | |
| Outpatient IV support | 0.73 | |||||
| H-OPAT | 1.00 (ref) | 1.00 (ref) | ||||
| S- OPAT | 0.94 ‡ | 0.45–1.96 | 0.87 | 0.86 † ‡ | 0.37–2.00 | |
| Healthcare funding source | <0.001 | |||||
| Medicare, Medicaid, private, charity | 1.00 (ref) | 1.00 (ref) | ||||
| Self-pay | 4.23 | 2.47–7.23 | <0.001 | 5.48 | 3.09–9.73 | |
| Race/ethnicity | 0.01 | |||||
| White, black, other | 1.00 (ref) | 1.00 (ref) | ||||
| Hispanic | 1.69 | 1.00–2.85 | 0.05 | 1.94 | 1.14–3.31 | |
| Diabetes mellitus | 0.01 | |||||
| No | 1.00 (ref) | 1.00 (ref) | ||||
| Yes | 0.06 | 0.01–0.46 | 0.006 | 0.08 | 0.01–0.60 | |
| Age | 0.002 | |||||
| <65 y | 1.00 (ref) | 1.00 (ref) | ||||
| ≥65 y | 2.71 | 1.56–4.71 | <0.001 | 2.48 | 1.41–4.37 | |
| Propensity score (quintiles) | 0.008 | |||||
| 1 | 1.00 (ref) | |||||
| 2 | 2.47 | 0.15–1.08 | 0.07 | |||
| 3 | 1.31 | 0.26–2.28 | 0.63 | |||
| 4 | 1.20 | 0.27–2.58 | 0.75 | |||
| 5 | 0.44 | 0.59–8.70 | 0.24 | |||
Model 1 controls for confounding with covariates; model 2 controls and for confounding with covariates and for selection bias with the propensity score.
*The p-values for the main category terms are the effects from the type 3 tests, and those for the individual category terms are the maximum likelihood estimates, all based on a sample size of 1,168.
‡Replication of the two models with multiple logistic regression analysis gave similar results for all estimates; specifically, the odds ratio for S-OPAT was 1.09 (95% CI 0.50–2.39) for model 1 and 1.05 (95% CI 0.43–2.55) for model 2.
†Reanalysis after excluding patients in quintiles 4 and 5 of the propensity score gave an aHR for S-OPAT of 0.82 (95% CI 0.35–1.91; p = 0.64). When the continuous propensity score was used in the model as a quadratic effect, the aHR for S-OPAT was 0.91 (95% CI 0.40–2.03; p = 0.81).
ref, referent category.