Table 2.
Hazard Ratio (95% Confidence Interval) of Critical Illness Mortality per Admission Year Category Provided, with 2006–2008 Considered as Reference for All Analyses
| Admission Year |
Multiplicative Interaction Term P Value | |||||
|---|---|---|---|---|---|---|
| 2006–2008 | 2009–2010 | 2011–2012 | 2013–2014 | 2015–2016 | ||
| All hospitals | Ref. | 0.86 (0.84–0.89) | 0.82 (0.80–0.84) | 0.81 (0.79–0.82) | 0.80 (0.78–0.82) | — |
| Minority-serving hospitals | Ref. | 0.83 (0.77–0.89) | 0.88 (0.82–0.95) | 0.79 (0.74–0.85) | 0.88 (0.81–0.94) | <0.001 |
| Non–minority-serving hospitals | Ref. | 0.87 (0.85–0.89) | 0.80 (0.79–0.82) | 0.81 (0.79–0.82) | 0.79 (0.77–0.81) | |
| Minority hospital defined as having greater than 25% African American or Hispanic census | ||||||
| Minority-serving hospitals | Ref. | 0.85 (0.80–0.90) | 0.83 (0.78–0.87) | 0.79 (0.75–0.83) | 0.85 (0.80–0.90) | 0.05 |
| Non–minority-serving hospitals | Ref. | 0.87 (0.84–0.89) | 0.81 (0.79–0.83) | 0.81 (0.79–0.83) | 0.79 (0.77–0.81) | |
| GEE analysis in hospitals with >500 admissions to account for hospital correlation | ||||||
| Minority-serving hospitals | Ref. | 0.94 (0.92–0.95) | 0.93 (0.91–0.95) | 0.90 (0.88–0.93) | 0.94 (0.91–0.97) | 0.05 |
| Non–minority-serving hospitals | Ref. | 0.94 (0.92–0.95) | 0.90 (0.88–0.92) | 0.89 (0.87–0.91) | 0.88 (0.86–0.90) | |
| Cox regression in hospitals with participation in four consecutive time periods | ||||||
| Minority-serving hospitals | Ref. | 0.82 (0.76–0.88) | 0.87 (0.81–0.94) | 0.75 (0.70–0.81) | 0.87 (0.81–0.94) | 0.003 |
| Non–minority-serving hospitals | Ref. | 0.87 (0.85–0.89) | 0.81 (0.79–0.83) | 0.82 (0.80–0.84) | 0.80 (0.77–0.82) | |
Definition of abbreviations: GEE = generalized estimating equation; Ref. = reference.
Adjusted hazard ratios for critical illness mortality according to admission year and hospital minority composition. Adjusted for age, sex, ethnicity, unit type, admission diagnosis, Charlson comorbidity score, and illness severity. In addition, alternative definition of hospital minority composition, and analytic approaches to account for within hospital correlation and hospital participation, are provided. Multiplicative interaction P value between indicator for minority-serving hospitals and admission year (defined continuously) provided.