Table 3.
Multivariable models of predictors of sentinel lymph node biopsy.
| Entire Cohort aRR | Minimally invasive hysterectomy aRR | 2014–2015 aRR | |
|---|---|---|---|
| Age | |||
| <40 | Referent | Referent | Referent |
| 40–49 | 0.68 (0.47–0.99)* | 0.64 (0.43–0.93)* | 0.79 (0.47–1.31) |
| 50–59 | 0.90 (0.65–1.24) | 0.84 (0.60–1.16) | 0.85 (0.54–1.34) |
| 60–69 | 1.01 (0.73–1.40) | 0.92 (0.66–1.28) | 0.87 (0.55–1.37) |
| ≥70 | 1.04 (0.73–1.47) | 0.91 (0.64–1.30) | 0.91 (0.56–1.49) |
| Year | |||
| 2011 | Referent | Referent | – |
| 2012 | 1.46 (1.14–1.88)* | 1.89 (1.41–2.53)* | – |
| 2013 | 3.41 (2.73–4.26)* | 4.50 (3.46–5.85)* | – |
| 2014 | 5.06 (4.06–6.30)* | 6.66 (5.13–8.64)* | Referent |
| 2015 | 6.26 (4.80–8.16)* | 8.43 (6.24–11.40)* | 1.17 (0.96–1.42) |
| Marital status | |||
| Married | Referent | Referent | Referent |
| Single | 0.95 (0.83–1.08) | 0.96 (0.84–1.10) | 1.02 (0.85–1.21) |
| Other/unknown | 1.24 (0.95–1.63) | 1.22 (0.91–1.64) | 1.22 (0.79–1.89) |
| Race | |||
| White | Referent | Referent | Referent |
| Black | 0.92 (0.71–1.18) | 0.85 (0.64–1.13) | 0.98 (0.69–1.39) |
| Other/unknown | 0.95 (0.80–1.12) | 0.91 (0.76–1.08) | 1.07 (0.84–1.35) |
| Insurance status | |||
| Commercial | Referent | Referent | Referent |
| Medicare | 0.89 (0.76–1.04) | 0.90 (0.77–1.06) | 0.91 (0.72–1.13) |
| Medicaid | 0.89 (0.69–1.14) | 0.90 (0.69–1.18) | 0.84 (0.59–1.21) |
| Uninsured | 0.72 (0.47–1.10) | 0.65 (0.39–1.08) | 0.61 (0.30–1.26) |
| Unknown | 1.19 (0.79–1.79) | 1.21 (0.78–1.86) | 1.05 (0.53–2.08) |
| Hospital location | |||
| Urban | Referent | Referent | – |
| Rural | 0.72 (0.23–2.26) | 0.61 (0.09–3.99) | – |
| Hospital teaching status | |||
| Teaching | Referent | Referent | Referent |
| Non-teaching | 0.81 (0.42–1.59) | 0.75 (0.30–1.87) | 0.53 (0.21–1.35) |
| Hospital bed size | |||
| <400 | Referent | Referent | Referent |
| 400–600 | 0.61 (0.30–1.23) | 0.65 (0.26–1.63) | 0.41 (0.15–1.13) |
| >600 | 0.49 (0.22–1.11) | 0.28 (0.09–0.89)* | 0.36 (0.12–1.08) |
| Hospital region | |||
| Northeastern | Referent | Referent | Referent |
| Midwest | 0.83 (0.35–2.00) | 1.11 (0.35–3.57) | 1.04 (0.31–3.52) |
| South | 0.80 (0.37–1.73) | 0.81 (0.28–2.37) | 0.63 (0.21–1.88) |
| West | 0.92 (0.36–2.39) | 1.15 (0.32–4.05) | 2.07 (0.55–7.83) |
| Comorbidity (Elixhauser) | |||
| 0 | Referent | Referent | Referent |
| 1 | 1.08 (0.89–1.30) | 1.12 (0.93–1.36) | 1.06 (0.82–1.36) |
| ≥2 | 1.19 (1.01–1.41)* | 1.22 (1.03–1.44)* | 1.11 (0.89–1.38) |
| Hysterectomy | |||
| Abdominal | Referent | – | Referent |
| Laparoscopic | 2.45 (1.89–3.18)* | Referent | 2.17 (1.40–3.36)* |
| Robotic | 2.69 (2.19–3.30)* | 1.06 (0.87–1.28) | 3.39 (2.41–4.79)* |
| Volume (increase in 1 unit) | 1.003 (0.995–1.012) | 1.009 (0.998–1.021) | 1.008 (0.997–1.020) |
*
P-value <0.05
aRR: adjusted risk ratio
Mixed-effect models were fitted accounting for hospital-level clustering using random-intercept log-Poisson regression models. The covariates included age, year, marital status, race, insurance status, hospital location, teaching status, bed size, region, comorbidity, route of hysterectomy and annualized hospital volume. Hospital location was not adjusted for in the model limiting to 2014–2015 because of convergence issue.