Table 4. Results of the Generalized Linear Mixed Model for Cost Variation for Autologous Free Flap Breast Reconstruction From 2008 to 2010 in the United Statesa.
| Variable | Exp[β] (95% CI) | P Value |
|---|---|---|
| Age at time of breast reconstruction | 1.00 (0.99-1.00) | <.001b |
| Insurance type | ||
| Medicare | 0.95 (0.90-1.01) | .10 |
| Medicaid | 0.92 (0.86-0.98) | .007b |
| Other | 0.94 (0.87-1.02) | .13 |
| Private | 1 [Reference] | NA |
| Race/ethnicity | ||
| Black | 1.08 (1.02-1.14) | .006b |
| Hispanic | 0.83 (0.79-0.87) | <.001b |
| Other minorities | 0.99 (0.93-1.05) | .78 |
| Unspecified | 1.02 (0.96-1.07) | .56 |
| White | 1 [Reference] | NA |
| Median household income national quartile | ||
| First | 0.96 (0.91-1.00) | .07 |
| Second | 0.99 (0.95-1.03) | .53 |
| Third | 1.01 (0.97-1.05) | .57 |
| Fourth | 1 [Reference] | NA |
| Hospital volume | ||
| 11-30 | 1.07 (1.03-1.11) | <.001b |
| ≥31 | 1.06 (1.02-1.11) | .003b |
| ≤10 | 1 [Reference] | NA |
| Hospital location | ||
| Midwest | 1.63 (1.54-1.72) | <.001b |
| South | 1.12 (1.07-1.17) | <.001b |
| West | 1.53 (1.46-1.61) | <.001b |
| Northeast | 1 [Reference] | NA |
| Charlson Comorbidity Index | ||
| 1 | 1.09 (1.03-1.16) | .004b |
| ≥2 | 1.03 (0.99-1.06) | .11 |
| 0 | 1 [Reference] | |
| Length of stay | 1.11 (1.10-1.11) | <.001b |
| Teaching hospital | ||
| Yes | 1.14 (1.08-1.22) | <.001b |
| No | 1 [Reference] | NA |
| Hospital type | ||
| Private | 1.34 (1.25-1.44) | <.001b |
| Government | 1 [Reference] | NA |
| Surgical complications | ||
| Yes | 1.18 (1.13-1.22) | <.001b |
| No | 1 [Reference] | NA |
| Systemic complications | ||
| Yes | 1.04 (1.01-1.08) | .02b |
| No | 1 [Reference] | NA |
| Hospital bed size | ||
| Medium | 0.82 (0.77-0.88) | <.001b |
| Large | 0.82 (0.78-0.86) | <.001b |
| Small | 1 [Reference] | NA |
Abbreviation: NA, not applicable.
a
From the 2008 to 2012 Healthcare Cost and Utilization Project National Inpatient Sample database.
b
Statistically significant at 95% level.