Table 2.
Segmented Logistic Regression Model Results
| Valve Surgery | Inpatient Mortality | |
|---|---|---|
| Model specifications | ||
| Baseline trend | 1.03 (1.01–1.05) | … |
| IDU | … | 0.79 (0.71–0.89) |
| IDU x Baseline trend | 0.99 (0.98–0.99) | … |
| Trend change | 0.96 (0.93–0.99) | 0.98 (0.97–0.99) |
| Age, per quarter | 0.99 (0.98–0.99) | 1.03 (1.02–1.03) |
| Female | 0.65 (0.6–0.7) | 0.94 (0.87–0.99) |
| Race | ||
| White | 1 (Referent) | 1 (Referent) |
| Black | 0.93 (0.82–1.06) | 0.96 (0.84–1.09) |
| Hispanic | 0.94 (0.8–1.09) | 0.92 (0.79–1.07) |
| Asian | 0.91 (0.72–1.15) | 1.18 (0.91–1.53) |
| Native American | 0.95 (0.64–1.41) | 1.09 (0.74–1.62) |
| Other | 1.18 (0.96–1.45) | 1.04 (0.83–1.29) |
| Payor | ||
| Medicaid | 1 (Referent) | 1 (Referent) |
| Medicare | 0.64 (0.58–0.71) | 1.07 (0.96–1.19) |
| Commercial | 1.32 (1.2–1.45) | 0.88 (0.79–0.98) |
| Self | 0.97 (0.86–1.1) | 1.12 (0.98–1.29) |
| No charge | 1.2 (0.87–1.64) | 0.86 (0.62–1.18) |
| Other | 1.11 (0.93–1.33) | 1.05 (0.87–1.28) |
| Zip code income quartile | ||
| Quartile 1 | 0.89 (0.84–0.96) | 1.10 (1.03–1.17) |
| Quartile 2 | 0.97 (0.91–1.03) | 1.02 (0.95–1.10) |
| Quartile 3 | 1.04 (0.98–1.12) | 0.93 (0.86–1.01) |
| Quartile 4 | 1 (Referent) | 1 (Referent) |
| Hospital region | ||
| Northeast | 1 (Referent) | 1 (Referent) |
| Midwest | 1.02 (0.93–1.12) | 0.95 (0.87–1.04) |
| South | 0.95 (0.88–1.03) | 1.03 (0.97–1.10) |
| West | 0.90 (0.82–0.99) | 1.00 (0.92–1.09) |
| Mortality risk score (0–4) | ||
| 0 | 12.61 (2.21–72.08) | 0.33 (0.03–3.41) |
| 1 | 1 (Referent) | 1 (Referent) |
| 2 | 0.76 (0.49–1.2) | 0.46 (0.24–0.86) |
| 3 | 1.09 (0.71–1.68) | 1.62 (0.97–2.70) |
| 4 | 1.65 (1.08–2.52) | 13.03 (7.87–21.56) |
| Disability risk score (0–4) | ||
| 0 | 0.11 (0.06–0.18) | 9.7 (1.39–67.48) |
| 1 | 1 (Referent) | 1 (Referent) |
| 2 | 1.24 (1.03–1.49) | 0.35 (0.17–0.70) |
| 3 | 0.89 (0.8–1.0) | 0.51 (0.42–0.62) |
| 4 | 1 | 1 |
| Non-elective admission | 0.7 (0.66–0.73) | 1.01 (0.93–1.08) |
Data are for valve surgery and inpatient mortality following implementation of public reporting (1 January 2010–31 August 2015). Values are adjusted odds ratios. IDU x Trend Change, Level Change, and IDU x Level Change are excluded from the table as these terms were removed from presented models. These are odds ratios which require a “referent” to which the other variables are compared. Abbreviation: IDU, injection drug use.