Table 3.
Multivariate logistic model for whether separate SES variables individually predict LOS>3 days (22%) among primary TKAs (n=2,194)
| With SES Variables | No SES Variables | |||||
|---|---|---|---|---|---|---|
| Variable | OR | 95% CI | P-Value | OR | 95% CI | P-Value |
| Race (ref = Non-Hispanic White) | ||||||
| Other | 2.39 | 1.35–4.25 | 0.003 | -- | -- | -- |
| Living Alone (ref = No) | ||||||
| Yes | 1.60 | 0.96–2.67 | 0.074 | -- | -- | -- |
| Missing | 1.42 | 0.69–2.89 | 0.340 | -- | -- | -- |
| Education (ref = Postgrad) | ||||||
| College | 1.51 | 0.79–2.88 | 0.216 | -- | -- | -- |
| Some College | 1.19 | 0.62–2.31 | 0.601 | -- | -- | -- |
| High School or Less | 1.29 | 0.68–2.44 | 0.430 | -- | -- | -- |
| Missing | 1.00 | 0.30–3.28 | 0.996 | -- | -- | -- |
| Employment (ref = Working/Student) | ||||||
| Retired, Not for Health | 0.81 | 0.47–1.39 | 0.440 | -- | -- | -- |
| Not Working | 1.65 | 0.98–2.77 | 0.058 | -- | -- | -- |
| Missing | 1.24 | 0.40–3.82 | 0.709 | -- | -- | -- |
| Household Annual Income (ref = $75,000+) | ||||||
| $50–75,000 | 2.16 | 0.88–5.32 | 0.093 | -- | -- | -- |
| $35–50,000 | 0.78 | 0.28–2.20 | 0.643 | -- | -- | -- |
| <$35,000 | 2.74 | 1.20–6.25 | 0.017 | -- | -- | -- |
| Refused to Answer | 1.15 | 0.51–2.62 | 0.732 | -- | -- | -- |
| Missing | 1.99 | 0.80–4.91 | 0.137 | -- | -- | -- |
| Surgeon (ref = Surgeon 1) | ||||||
| Surgeon 2 | 2.60 | 1.76–3.84 | <0.001 | 2.61 | 1.78–3.83 | <0.001 |
| Surgeon 3 | 2.64 | 0.90–7.73 | 0.077 | 2.48 | 0.86–7.12 | 0.091 |
| Surgeon 4* | -- | -- | -- | -- | -- | -- |
| Surgeon 5 | 1.44 | 0.56–3.71 | 0.449 | 1.45 | 0.58–3.61 | 0.426 |
| Surgeon 6 | 1.82 | 1.23–2.70 | 0.003 | 1.82 | 1.23–2.70 | 0.003 |
| Surgeon 7 | 2.62 | 1.81–3.78 | <0.001 | 2.65 | 1.85–3.81 | <0.001 |
| Surgeon 8 | 1.06 | 0.56–2.03 | 0.857 | 1.14 | 0.61–2.15 | 0.675 |
| Surgeon 9 | 0.49 | 0.17–1.40 | 0.183 | 0.52 | 0.18–1.48 | 0.218 |
| Surgeon 10 | 1.73 | 1.10–2.73 | 0.018 | 1.70 | 1.08–2.67 | 0.022 |
| Age Group (ref = <55) | ||||||
| 55–59 | 0.95 | 0.62–1.45 | 0.800 | 0.91 | 0.60–1.39 | 0.670 |
| 60–64 | 0.90 | 0.60–1.36 | 0.629 | 0.88 | 0.59–1.32 | 0.538 |
| 65–69 | 1.20 | 0.82–1.78 | 0.350 | 1.17 | 0.80–1.72 | 0.427 |
| 70–74 | 1.29 | 0.83–2.02 | 0.260 | 1.22 | 0.79–1.87 | 0.375 |
| 75–79 | 2.11 | 1.32–3.36 | 0.002 | 1.89 | 1.21–2.97 | 0.005 |
| 80+ | 2.58 | 1.56–4.26 | <0.001 | 2.38 | 1.45–3.89 | 0.001 |
| Sex (ref = Male) | ||||||
| Female | 1.20 | 0.95–1.53 | 0.123 | 1.24 | 0.98–1.56 | 0.072 |
| Preoperative Alcohol Use (ref = No) | ||||||
| Yes | 0.71 | 0.55–0.90 | 0.004 | 0.66 | 0.52–0.84 | 0.001 |
| Preoperative Tobacco Use (ref = Never) | ||||||
| Quit | 1.18 | 0.93–1.49 | 0.176 | 1.20 | 0.95–1.52 | 0.127 |
| Yes | 1.15 | 0.70–1.88 | 0.577 | 1.29 | 0.80–2.09 | 0.296 |
| Charlson Score (ref = 0) | ||||||
| 1 | 1.41 | 1.06–1.86 | 0.016 | 1.38 | 1.05–1.84 | 0.021 |
| 2+ | 1.64 | 1.22–2.20 | 0.001 | 1.62 | 1.22–2.17 | 0.001 |
| VR-12 PCS Preoperative (ref = 50+) | ||||||
| 40–49.99 | 2.43 | 1.17–5.01 | 0.017 | 2.62 | 1.28–5.36 | 0.008 |
| 30–39.99 | 2.99 | 1.49–5.96 | 0.002 | 3.20 | 1.62–6.32 | 0.001 |
| 20–29.99 | 2.94 | 1.48–5.85 | 0.002 | 2.17 | 1.62–6.23 | 0.001 |
| <20 | 4.55 | 2.18–9.46 | <0.001 | 4.93 | 2.41–10.09 | <0.001 |
| VR-12 MCS Preoperative (ref = 60+) | ||||||
| 50–59.99 | 1.17 | 0.85–1.60 | 0.328 | 1.23 | 0.90–1.67 | 0.198 |
| 40–49.99 | 1.53 | 1.08–2.17 | 0.017 | 1.63 | 1.15–2.31 | 0.006 |
| 30–39.99 | 1.94 | 1.32–2.84 | 0.001 | 2.10 | 1.44–3.07 | <0.001 |
| <30 | 1.30 | 0.76–2.23 | 0.342 | 1.36 | 0.80–2.30 | 0.255 |
| Year (ref = 2011) | ||||||
| 2012 | 0.61 | 0.42–0.91 | 0.015 | 0.64 | 0.44–0.95 | 0.026 |
| 2013 | 0.73 | 0.49–1.09 | 0.123 | 0.66 | 0.45–0.96 | 0.032 |
| 2014 | 0.80 | 0.51–1.25 | 0.324 | 0.75 | 0.48–1.15 | 0.189 |
| 2015 | 0.47 | 0.28–0.78 | 0.004 | 0.41 | 0.25–0.68 | 0.012 |
| 2016 | 0.37 | 0.13–1.03 | 0.055 | 0.36 | 0.14–0.97 | 0.042 |
| Bilateral TKA (ref = No) | ||||||
| Yes | 2.53 | 1.96–3.27 | <0.001 | 2.39 | 1.86–3.08 | <0.001 |
| BMI Preoperative (ref = Normal, <25) | ||||||
| Overweight, 25–29.99 | 0.94 | 0.63–1.39 | 0.741 | 0.91 | 0.62–1.35 | 0.648 |
| Obese, 30–34.99 | 1.10 | 0.73–1.65 | 0.641 | 1.11 | 0.75–1.65 | 0.597 |
| Severe Obese, 35–39.99 | 1.28 | 0.83–1.98 | 0.258 | 1.32 | 0.86–2.02 | 0.200 |
| Morbid Obese, 40+ | 1.61 | 1.02–2.55 | 0.040 | 1.64 | 1.04–2.56 | 0.031 |
| 10-fold cross-validation AUC | ||||||
| 0.76 | 0.74–0.79 | 0.74 | 0.72–0.77 | |||
Clustered on 2,057 patients and using robust standard errors to account for observational data. Surgeon 4 performed 4 surgeries in this time period and they were excluded from this analysis for lack of variation.