Table 6. Multivariate analysis of co-morbidities with median length of stay (mLOS).

Variables	Correlation coefficient	P value
Total morphine equivalence (TME)	0.548	<0.001
Average post-surgical pain score	−0.284	0.006
Use of PCA	0.213	0.011
PMH: COPD	0.251	0.003
PMH: diabetes, type I	0.160	0.041
PMH: psychiatric disorder	0.087	0.302
PMH: mobility disorder	0.134	0.121
Duration of surgery (min)	0.113	0.138
BMI	0.001	0.995
PMH: tobacco usage	−0.133	0.138
Chronic pain	−0.132	0.151
On pain meds before surgery	0.062	0.473
Use of Alvimopan	−0.103	0.249
PMH: diabetes, type II	0.221	0.120

PCA, patient-controlled analgesia; COPD, chronic obstructive pulmonary disease; PMH, past medical history; BMI, body mass index.