Table 2.
Adjusted Predictors of DAMA, Including All Patient Characteristics (Model 4), and with Hospital Characteristics Added (Model 5)
| Model 4: All Patient Characteristics | Model 5: Hospital Characteristics Added | |||||
|---|---|---|---|---|---|---|
| OR | P | 95% CI | OR | P | 95% CI | |
| Patient characteristics | ||||||
| Race/ethnicity | ||||||
| White | 1.00 | – | 1.00 | – | ||
| Black | 1.23 | <.001 | 1.16 to 1.31 | 0.95 | .05 | 0.91 to 1.00 |
| Hispanic | 0.90 | .03 | 0.82 to 0.99 | 0.66 | <.001 | 0.62 to 0.70 |
| Asian | 0.76 | <.001 | 0.69 to 0.84 | 0.60 | <.001 | 0.55 to 0.65 |
| Other | 0.95 | .49 | 0.81 to 1.10 | 0.69 | <.001 | 0.61 to 0.78 |
| Missing | 0.88 | .24 | 0.72 to 1.09 | 0.72 | .001 | 0.60 to 0.87 |
| Female gender | 0.62 | <.001 | 0.61 to 0.63 | 0.62 | <.001 | 0.61 to 0.63 |
| Patient age | 0.84 | <.001 | 0.83 to 0.84 | 0.83 | <.001 | 0.82 to 0.84 |
| Patient age squared | 0.997 | <.001 | 0.997 to 0.998 | 0.997 | <.001 | 0.997 to 0.998 |
| Elective admission | 0.23 | <.001 | 0.21 to 0.26 | 0.24 | <.001 | 0.22 to 0.27 |
| Primary payer | ||||||
| Private insurance | 1.00 | – | 1.00 | – | ||
| Self-pay | 3.39 | <.001 | 3.16 to 3.62 | 3.08 | <.001 | 2.89 to 3.29 |
| Medicare | 1.97 | <.001 | 1.89 to 2.05 | 1.96 | <.001 | 1.89 to 2.03 |
| Medicaid | 3.15 | <.001 | 2.99 to 3.32 | 2.81 | <.001 | 2.66 to 2.96 |
| Other | 1.60 | <.001 | 1.45 to 1.77 | 1.57 | <.001 | 1.44 to 1.70 |
| Patient median Zip code income | ||||||
| <$32,000 | 1.47 | <.001 | 1.33 to 1.63 | 1.30 | <.001 | 1.19 to 1.42 |
| $32,000 to <$40,000 | 1.20 | <.001 | 1.10 to 1.32 | 1.15 | .001 | 1.06 to 1.25 |
| $40,000 to <$53,000 | 1.16 | <.001 | 1.07 to 1.25 | 1.12 | .001 | 1.05 to 1.20 |
| $53,000+ | 1.00 | – | 1.00 | – | ||
| Missing patient Zip code | 1.83 | <.001 | 1.69 to 1.99 | 1.80 | <.001 | 1.67 to 1.95 |
| Hospital attributes | ||||||
| Log of total annual discharges | 0.85 | <.001 | 0.80 to 0.90 | |||
| Herfindahl Index* | 1.01 | .15 | 1.00 to 1.02 | |||
| Hospital ownership | ||||||
| Not-for-profit | 1.00 | – | ||||
| Public | 0.95 | .47 | 0.84 to 1.09 | |||
| Private | 1.20 | <.001 | 1.09 to 1.33 | |||
| Teaching hospital | 1.06 | .04 | 1.00 to 1.13 | |||
| Hospital utilization rate | ||||||
| Quartile 1 | 1.00 | – | ||||
| Quartile 2 | 1.02 | .73 | 0.92 to 1.12 | |||
| Quartile 3 | 1.07 | .28 | 0.94 to 1.22 | |||
| Quartile 4 | 0.94 | .33 | 0.84 to 1.06 | |||
| Hospital environment | ||||||
| Hospital MSA size | ||||||
| Nonmetropolitan | 1.74 | <.001 | 1.57 to 1.93 | |||
| <1 M | 1.28 | <.001 | 1.17 to 1.41 | |||
| 1 M to 2.5 M | 1.00 | – | ||||
| >2.5 M | 1.02 | .80 | 0.89 to 1.16 | |||
| Hospital percent Medicaid discharges† | 1.03 | .001 | 1.01 to 1.05 | |||
| Hospital percent Nonwhite discharges‡ | 1.03 | <.001 | 1.02 to 1.04 | |||
Models also adjusted for individual patient co-morbidities, year of discharge, and state (not shown). ORs for age are for 5-year increments in age.
*
The Herfindahl index (0 to 1) is multiplied by 100. (Sample inter-quartile range 6 to 12.)
†
ORs for percent Medicaid discharges are for 5% increments in hospital percent Medicaid discharges.
‡
ORs for percent nonwhites discharges are for 5% increments in hospital percent nonwhite discharges.
DAMA, discharged against medical advice; OR, odds ratio; CI, confidence intervals.