Table III.
Multivariate Regression of Costs, Length of Stay, and Mortality Among Patients With or Without Sickle Disease Undergoing Cholecystectomy or Hip Replacement*
| Variable | Cholecystectomy | Hip Replacement | ||
|---|---|---|---|---|
| In-Hospital Costs | ||||
| Cost Ratio (95% CI) | P Value | Cost Ratio (95% CI) | P Value | |
| Constant | 14,031 (13,439–14,649) | < 0.001 | 37,235 (34,903–39,723) | < 0.001 |
| Sickle cell disease | 1.43 (1.34–1.52) | < 0.001 | 1.25 (1.20–1.31) | < 0.001 |
| Laparoscopic surgery | 0.50 (0.49–0.50) | < 0.001 | — | |
| Elective surgery | 0.83 (0.82–0.84) | < 0.001 | 0.84 (0.83–0.85) | < 0.001 |
| Age (decades) | 1.04 (1.03–1.04) | < 0.001 | 0.98 (0.98–0.99) | < 0.001 |
| Primary expected payer | ||||
| Private | 1.00 [Reference] | 1.00 [Reference] | ||
| Medicare | 1.15 (1.13–1.18) | < 0.001 | 1.05 (1.04–1.07) | < 0.001 |
| Medicaid | 1.16 (1.15–1.18) | < 0.001 | 1.07 (1.05–1.09) | < 0.001 |
| Self-pay | 1.06 (1.04–1.08) | < 0.001 | 1.03 (0.99–1.07) | 0.14 |
| No charge | 1.26 (1.21–1.31) | < 0.001 | 0.99 (0.90–1.08) | 0.79 |
| Other | 1.07 (1.04–1.09) | < 0.001 | 1.04 (1.02–1.07) | < 0.001 |
| Male sex | 1.20 (1.19–1.22) | < 0.001 | 1.01 (1.00–1.02) | 0.02 |
| Hospital size | ||||
| Small | 1.00 [Reference] | 1.00 [Reference] | ||
| Medium | 1.17 (1.14–1.20) | < 0.001 | 0.84 (0.82–0.85) | < 0.001 |
| Large | 1.10 (1.07–1.12) | < 0.001 | 0.80 (0.79–0.81) | < 0.001 |
| Urban hospital | 0.98 (0.96–1.00) | 0.10 | 0.67 (0.64–0.71) | < 0.001 |
| Hospital ownership | ||||
| Not specified | 1.00 [Reference] | 1.00 [Reference] | ||
| Public | 1.06 (1.04–1.09) | < 0.001 | 0.88 (0.85–0.92) | < 0.001 |
| Private | 1.12 (1.09–1.14) | < 0.001 | 0.80 (0.78–0.82) | < 0.001 |
| US geographic region | ||||
| Northeast | 1.00 [Reference] | 1.00 [Reference] | ||
| Midwest | 1.04 (1.03–1.06) | < 0.001 | 0.96 (0.95–0.98) | < 0.001 |
| South | 0.99 (0.98–1.01) | 0.22 | 1.07 (1.06–1.09) | < 0.001 |
| West | 1.24 (1.22–1.26) | < 0.001 | 1.25 (1.23–1.27) | < 0.001 |
| Teaching hospital | 1.21 (1.19–1.23) | < 0.001 | 1.00 (0.97–1.02) | 0.69 |
| Length of Stay | ||||
| Length of Stay Ratio (95% CI) | P Value | Length of Stay Ratio (95% CI) | P Value | |
| Constant | 4.95 (4.69–5.22) | < 0.001 | 5.76 (5.21–6.36) | < 0.001 |
| Sickle cell disease | 1.70 (1.59–1.81) | < 0.001 | 1.56 (1.47–1.64) | < 0.001 |
| Laparoscopic surgery | 0.46 (0.46–0.47) | < 0.001 | — | — |
| Elective surgery | 0.69 (0.69–0.70) | < 0.001 | 0.67 (0.66–0.68) | < 0.001 |
| Age (decades) | 1.61 (1.06–1.07) | < 0.001 | 1.01 (1.00–1.02) | 0.07 |
| Primary expected payer | ||||
| Private | 1.00 [Reference] | 1.00 [Reference] | ||
| Medicare | 1.23 (1.20–1.25) | < 0.001 | 1.12 (1.10–1.14) | < 0.001 |
| Medicaid | 1.27 (1.25–1.29) | < 0.001 | 1.22 (1.19–1.25) | < 0.001 |
| Self-pay | 1.12 (1.10–1.14) | < 0.001 | 1.19 (1.13–1.25) | < 0.001 |
| No charge | 1.19 (1.14–1.24) | < 0.001 | 1.34 (1.21–1.48) | < 0.001 |
| Other | 1.18 (1.14–1.21) | < 0.001 | 1.17 (1.13–1.21) | < 0.001 |
| Male sex | 1.20 (1.18–1.21) | < 0.001 | 0.95 (0.94–0.96) | < 0.001 |
| Hospital size | ||||
| Small | 1.00 [Reference] | 1.00 [Reference] | ||
| Medium | 1.11 (1.08–1.14) | < 0.001 | 0.94 (0.91–0.96) | < 0.001 |
| Large | 1.15 (1.12–1.18) | < 0.001 | 0.91 (0.89–0.93) | < 0.001 |
| Urban hospital | 1.07 (1.04–1.11) | < 0.001 | 1.05 (0.97–1.14) | 0.22 |
| Hospital ownership | ||||
| Not specified | 1.00 [Reference] | 1.00 [Reference] | ||
| Public | 1.02 (0.99–1.05) | 0.26 | 0.85 (0.81–0.90) | < 0.001 |
| Private | 0.95 (0.93–0.98) | < 0.001 | 0.91 (0.87–0.95) | < 0.001 |
| US geographic region | ||||
| Northeast | 1.00 [Reference] | 1.00 [Reference] | ||
| Midwest | 1.01 (1.00–1.03) | 0.16 | 0.93 (0.91–0.96) | < 0.001 |
| South | 1.04 (1.03–1.06) | < 0.001 | 0.93 (0.91–0.95) | < 0.001 |
| West | 0.97 (0.95–0.99) | 0.002 | 0.92 (0.90–0.95) | < 0.001 |
| Teaching hospital | 1.06 (1.04–1.08) | < 0.001 | 0.94 (0.91–0.98) | < 0.001 |
| In-Hospital Mortality | ||||
| Odds Ratio (95% CI) | P Value | Odds Ratio (95% CI) | P Value | |
| Constant | 0.002 (0.001–0.006) | 0 | ||
| Sickle cell disease | 1.55 (0.58–4.14) | 0.39 | 0.55 (0.06–4.74) | 0.59 |
| Laparoscopic surgery | 0.16 (0.13–0.20) | < 0.001 | — | — |
| Elective surgery | 0.69 (0.55–0.87) | 0.001 | 0.29 (0.15–0.56) | < 0.001 |
| Age (decades) | 1.36 (1.23–1.50) | < 0.001 | 1.24 (0.87–1.77) | 0.24 |
| Primary expected payer | ||||
| Private | 1.00 [Reference] | 1.00 [Reference] | ||
| Medicare | 1.80 (1.40–2.33) | 0.08 | 4.48 (2.26–8.90) | < 0.001 |
| Medicaid | 1.30 (0.97–1.74) | < 0.001 | 2.86 (1.21–6.77) | 0.02 |
| Self-pay | 1.22 (0.84–1.77) | 0.31 | 1.70 (0.33–8.64) | 0.53 |
| No charge | 1.09 (0.44–2.70) | 0.85 | 1.00 (1.00–1.00) | > 0.99 |
| Other | 1.34 (0.84–2.14) | 0.23 | 1.95 (0.42–9.01) | 0.39 |
| Male sex | 1.72 (1.41–2.09) | < 0.001 | 0.82 (0.46–1.47) | 0.49 |
| Hospital size | ||||
| Small | 1.00 [Reference] | 1.00 [Reference] | ||
| Medium | 1.31 (0.76–2.27) | 0.33 | 1.68 (0.47–6.01) | 0.42 |
| Large | 1.19 (0.71–1.97) | 0.52 | 1.35 (0.48–3.81) | 0.57 |
| Urban hospital | 1.36 (0.76–2.46) | 0.30 | 1.00 (1.00–1.00) | — |
| Hospital ownership | ||||
| Not specified | 1.00 [Reference] | 1.00 [Reference] | ||
| Public | 1.35 (0.77–2.38) | 0.30 | 1.11 (0.06–20.91) | 0.94 |
| Private | 1.07 (0.67–1.72) | 0.76 | 1.65 (0.16–17.32) | 0.67 |
| US geographic region | ||||
| Northeast | 1.00 [Reference] | 1.00 [Reference] | ||
| Midwest | 0.82 (0.59–1.14) | 0.24 | 1.03 (0.42–2.54) | 0.95 |
| South | 0.96 (0.72–1.29) | 0.81 | 0.96 (0.42–2.19) | 0.93 |
| West | 0.85 (0.59–1.24) | 0.39 | 0.18 (0.02–1.58) | 0.13 |
| Teaching hospital | 0.95 (0.64–1.41) | 0.81 | 2.23 (0.26–19.22) | 0.47 |
Abbreviation: CI, confidence interval.
*
Regression models included all of the variables listed plus 29 comorbid conditions.