Table 2.
Multivariable negative binomial regression of factors associated with length of stay, stratified by frailty status (patient of the surgical cohort taking one or more medication)
| Variable | Robust group (n = 123) | Vulnerable group (n = 85) | Frail group (n = 44) | |||
|---|---|---|---|---|---|---|
| IRR (95% CI) | p value | IRR (95% CI) | p value | IRR (95% CI) | p value | |
| Age | 1.03 (0.99–1.07) | 0.153 | 1.01 (0.97–1.06) | 0.561 | 0.99 (0.93–1.06) | 0.811 |
| Charlson Comorbidity Scorea | 1.02 (0.88–1.20) | 0.761 | 0.88 (0.75–1.02) | 0.098 | 0.89 (0.71–1.12) | 0.322 |
| Surgery specialty | ||||||
| Orthopedics | 1 | 1 | 1 | |||
| General surgery | 1.60 (0.93–2.75) | 0.089 | 1.06 (0.57–1.98) | 0.666 | 1.03 (0.37–2.87) | 0.949 |
| Vascular surgery | 1.40 (0.69–2.83) | 0.348 | 1.51 (0.75–3.01) | 0.224 | 0.59 (0.17–2.01) | 0.409 |
| Sex | ||||||
| Female | 1 | 1 | 1 | |||
| Male | 1.02 (0.65–1.60) | 0.919 | 0.85 (0.50–1.44) | 0.544 | 0.63 (0.31–1.28) | 0.628 |
| Number of PIMs | 1.10 (0.89–1.67) | 0.327 | 1.20 (0.98–1.44) | 0.089 | 0.96 (0.79–1.17) | 0.692 |
CI confidence interval, IRR incidence relative ratio, PIMs potentially inappropriate medications
aCharlson Comorbidity Score = comorbidities of the Charlson Comorbidity Index