Table 4. Poisson multiple regression assessing the association of SMI with non-psychiatric hospitalization over time-intervals from ≤ 30 Days through 2-years post-stroke.
| ≤ 30 Days | 31to 90 Days | 91 to 364 Days | 1 to < 2 Years | |
|---|---|---|---|---|
| History of Severe Mental Illness | 1.78 [0.89–2.49] | .83[.54–1.21] | 1.34 [.91–1.98] | .85 [.54–1.29] |
| Age 45–64 years (ref 18–44) | 1.20 [.71–2.03] | 1.13 [.66–1.95] | .69 [.39–1.23] | 1.10 [.55–2.22] |
| Age 65–74 years (ref 18–44) | .95 [.52–1.75] | .81 [.44–1.47] | .86 [.45–1.67] | .90 [.42–1.94] |
| Age > 75 years (ref 18–44) | 1.12 [.61–2.03] | 1.18 [.65–2.15] | .91 [.47–1.75] | 1.35 [.63–2.82] |
| Race (ref White) | 1.23 [.91–1.67] | 1.03 [.78–1.34] | .66 [.46–.91]** | .78 [.56–1.09] |
| Elixhauser Index | 1.09 [.96–1.22] | 1.04 [.94–1.09] | 1.21 [1.12–1.33]*** | 1.13 [1.02–1.24]* |
| Pre-Stroke Hospitalizations | .98 [.95–1.04] | .99 [.95–1.03] | 1.01 [.96–1.10] | 1.06 [1.01–1.11]** |
| History of PTSD | .82 [.59–1.13] | .78 [.58–1.05] | removed | 1.03 [.71–1.50] |
| History of Depression | removed | removed | removed | removed |
| History of Substance Abuse | .99 [.68–1.44] | .97 [.67–1.39] | .98 [.63–1.51] | .50 [.30–.81]* |
| History of Hypertension | .91 [.61–1.36] | .90 [.62–1.30] | .79 [.50–1.28] | .98 [.59–1.61] |
| History of Diabetes | .93 [.69–1.24] | 1.13 [.87–1.46] | .95 [.66–1.35] | 1.39 [.98–1.97] |
| History of Peripheral Vascular Disease | .94 [.72–1.54] | 1.11 [.79–1.55] | .75 [.47–1.18] | .73 [.46–1.14] |
| Income | 1.00 [1.00–1.00] | 1.00 [1.0–1.0] | 1.00 [1.0–1.0] | 1.00 [1.0–1.0] |
| Insurance Status | .96 [.72–1.29] | 1.07 [.82–1.39] | 1.03 [.72–1.45] | .87 [.62–1.23] |
| Marital Status | .89 [.68–1.18] | .99 [.77–1.29] | .89 [.63–1.24] | .84 [.60–1.15] |
| Distance from VA to Home | .99 [.99–1.01] | .99 [.98–1.0] | .99 [.98–1.01] | .99 [.97–1.00]† |
| Discharged on a Statin | 1.03 [.78–1.36] | .90 [.71–1.17] | .98 [.68–1.37] | .63 [.45–.88]** |
| Antithrombotic at Discharge | .62 [.50–.74]* | .81 [.59–1.02] † | .90 [.51–1.56] | .69 [.51–1.09] |
| Assessed for Rehabilitation | 1.18 [.87–1.64] | .91 [.67–1.24] | .83 [.54–1.24] | .71 [.48–1.07] |
| Length of Hospital Stay | 1.02 [.77–1.34] | 1.01 [.78–1.32] | 1.19 [1.07–1.30]* | 1.11 [.90–1.31] |
| Observations Used (N) | 493 | 454 | 437 | 397 |
| Value/df | 1.04 | 1.06 | .86 | .86 |
| Null Scale Deviance | 537.0 | 564.6 | 362.8 | 332.8 |
| Scaled Deviance | 468.7 | 490.3 | 356.7 | 322.9 |
| AIC (smaller is better) | 841.0 | 930.2 | 1257.2 | 1199.2 |
The values in the table are the Relative Risks [95% Confidence Intervals] where statistical significance is denoted by ***p<0.001, **p<0.01, *p<0.05, †p<0.10.
Cells indicating “removed” were not considered in the model due to multicollinearity with SMI. Risk for increased hospitalization was calculated by taking the estimated Poisson regression coefficient (β) for each variable and transforming it by eβ [exp*confidence interval] of each independent variable for the model. The ratio of value to degrees of freedom (value/df) when close to 1.0 indicates adequate fit. A null model was fit with only SMI and no covariates and its scaled null deviance indicates the total variance available for explanation. The scaled deviance indicates the amount of variance explained by the model.