How do risk factors for mortality and overall complication rates following laparoscopic and open colectomy differ between inpatient and post-discharge phases of care? A retrospective cohort study from NSQIP.

BACKGROUND: Risk factors for complications differ between laparoscopic (LC) and open colectomy (OC) patients, given the selection bias between these groups. How risk factors for these outcomes differ between inpatient and post-discharge phases of care requires further study.
METHODS: A retrospective cohort study (2005-2010) using NSQIP data was performed comparing OC and LC patients. Multivariable logistic regression was used to compare covariates associated with mortality and overall complication rates both before and after hospital discharge.
RESULTS: Patients in the LC cohort were younger (64.2 vs. 62.5 years; P < 0.0001) with a lower incidence of comorbidities. OC was associated with a higher incidence of mortality compared to LC among inpatients (3.3 vs. 0.61%, P < 0.0001) and following discharge (0.88 vs. 0.29%, P < 0.0001). OC also demonstrated a higher incidence of overall complication rates for both inpatients (22.32 vs. 9.36%, P < 0.0001) and following discharge (8.83 vs. 7.24%, P < 0.0001). Risk factors (P < 0.05) for mortality following LC included age and emergency procedures for inpatients; pre-operative SIRS was associated with mortality occurring after discharge. For the OC cohort, risk for mortality was increased with smoking and contaminated/dirty wounds for inpatients; pre-operative weight loss was associated with death following discharge. Factors associated with increased risk of morbidity following LC included smoking history for inpatients and pre-operative steroid therapy following discharge. Following OC, morbidity was strongly associated with ASA scores for inpatients; pre-operative steroid therapy was a risk factor following discharge. Obesity was strongly associated with non-mortal complications in both cohorts following discharge.
CONCLUSIONS: (1) LC is associated with a lower incidence of post-operative mortality and complications. (2) Risk factors associated with adverse post-operative outcomes change during the post-operative period; surveillance for these outcomes should be tailored by operative technique and phase of post-operative care (3) Obesity is an underappreciated risk for complications following discharge for both LC and OC.