Table 2.
Multivariable Logistic Regression Models with Discharge Against Medical Advice as Outcome for All Infective Endocarditis and Stratified by Injection Drug Use
| Full Cohort n = 30 892 Weighted n = 153 616 | IDU n = 7259 Weighted n = 36 133 | Non-IDU n = 23 633 Weighted n = 117 482 | ||
|---|---|---|---|---|
| Adjusted OR (95% CI) | Adjusted OR (95% CI) | Adjusted OR (95% CI) | ||
| IDU | 3.92 (3.43–4.48) | N/A | N/A | |
| Time | 1.10 (1.06–1.15) | 1.12 (1.07–1.18) | 1.06 (1.00–1.13) | |
| Age, y | ||||
| 18–24 | 3.34 (2.60–4.31) | 3.02 (2.10–4.34) | 2.94 (1.85–4.67) | |
| 25–34 | 3.33 (2.71–4.10) | 2.87 (2.08–3.95) | 4.01 (2.97–5.40) | |
| 35–44 | 2.54 (2.05–3.14) | 2.31 (1.66–3.21) | 2.65 (1.98–3.54) | |
| 45–55 | 1.62 (1.32–1.99) | 1.61 (1.16–1.41) | 1.56 (1.18–2.06) | |
| 56–65 | Ref | Ref | Ref | |
| Female | 1.00 (.89–1.13) | 1.21 (1.04–1.41) | 0.71 (.58–.87) | |
| Race/ethnicity a | ||||
| White | Ref | Ref | Ref | |
| Black | 1.16 (.98–1.38) | 1.13 (.89–1.45) | 1.17 (.92–1.50) | |
| Hispanic | 1.07 (.88–1.30) | 1.32 (1.03–1.69) | 0.76 (.53–1.09) | |
| Asian | 0.39 (.17–.86) | 0.59 (.18–1.94) | 0.27 (.09–.86) | |
| Native American | 0.65 (.30–1.44) | 1.01 (.42–2.46) | <0.001 (<.001–<.001) | |
| Other | 1.09 (.72–1.66) | 0.99 (.62–1.59) | 1.21 (.69–2.14) | |
| Payor | ||||
| Medicare | 0.77 (.65–.92) | 0.75 (.58–.96) | 0.75 (.58–.98) | |
| Medicaid | Ref | Ref | Ref | |
| Commercial | 0.44 (.36–.54) | 0.57 (.44–.74) | 0.35 (.26–.47) | |
| Self | 1.39 (1.18–1.65) | 1.37 (1.13–1.66) | 1.44 (1.06–1.95) | |
| No charge | 1.31 (.90–1.92) | 1.24 (.79–1.94) | 1.61 (.81–3.19) | |
| Other | 0.73 (.52–1.02) | 0.70 (.46–1.05) | 0.79 (.47–1.33) | |
| ZIP code income quartile | ||||
| Quartile 1 | 1.57 (1.28–1.92) | 1.56 (1.21–1.99) | 1.57 (1.11–2.42) | |
| Quartile 2 | 1.25 (1.01–1.55) | 1.24 (.96–1.60) | 1.25 (.87–1.81) | |
| Quartile 3 | 1.22 (.98–1.51) | 1.16 (.89–1.52) | 1.30 (.91–1.87) | |
| Quartile 4 | Ref | Ref | Ref | |
| Hospital region | ||||
| Northeast | Ref | Ref | Ref | |
| Midwest | 0.74 (.61–.91) | 0.81 (.63–1.04) | 0.62 (.44–.87) | |
| South | 0.63 (.53–.75) | 0.60 (.48–.75) | 0.69 (.53–.89) | |
| West | 0.93 (.77–1.12) | 0.84 (.67–1.06) | 1.13 (.83–1.54) | |
| Hospital location/teaching status | ||||
| Rural | Ref | Ref | Ref | |
| Urban, nonteaching | 1.20 (.93–1.56) | 1.12 (.82–1.53) | 1.38 (.91–2.09) | |
| Urban, teaching | 0.95 (.74–1.22) | 0.91 (.67–1.24) | 1.03 (.69–1.55) | |
| Hospital bed size | ||||
| Small | Ref | Ref | Ref | |
| Medium | 0.84 (.70–1.02) | 0.96 (.76–1.22) | 0.68 (.50–.92) | |
| Large | 0.70 (.59– .83) | 0.76 (.61–.94) | 0.61 (.47–.80) | |
| Modified Elixhauser score b | ||||
| 0 | Ref | Ref | Ref | |
| 1–2 | 0.61 (.47–.78) | 0.71 (.53–.95) | 0.40 (.26–.60) | |
| 3–4 | 0.39 (.30–.51) | 0.41 (.30–.55) | 0.33 (.22–.51) | |
| ≥5 | 0.33 (.25–.42) | 0.31 (.23–.44) | 0.30 (.20–.46) | |
| Alcohol | 1.11 (.91–1.35) | 0.92 (.73–1.16) | 1.61 (1.16–2.24) | |
| Cannabis | 1.37 (1.07–1.74) | 1.26 (.96–1.65) | 2.0 (1.20–3.33) | |
| Sedative | 0.94 (.58–1.52) | 1.05 (.64–1.71) | 1.27 (.13–12.37) | |
| Psychoses | 1.28 (1.07–1.54) | 0.96 (.59–1.56) | 1.78 (1.28–2.47) | |
| Depression | 1.03 (.87–1.22) | 0.97 (.79–1.18) | 1.14 (.85–1.54) | |
| Elective | 0.59 (.46–.76) | 0.58 (.42–.80) | 0.63 (.43–.91) | |
| CT surgery | 0.20 (.14–.27) | 0.23 (.16–.33) | 0.14 (.08–.28) |
Abbreviations: AMA, against medical advice; CI, confidence interval; CT, cardiothoracic; IDU, injection drug use; N/A, not available; OR, odds ratio.
aIn the National Inpatient Sample, hospitalized individuals are categorized by Hispanic ethnic exclusive of other racial categories.
bElixhauser score contains 30 components weighted equally and is used to adjust for inpatient comorbidities. We included 26 of these components in the modified Elixhauser. We separated drug use, psychoses, depression, and alcohol use because these conditions have been previously associated with AMA discharge and IDU status.