Surgical Start Time Is Not Predictive of Microdiscectomy Outcomes.

STUDY DESIGN: Retrospective analysis of clinical data from a single institution.

OBJECTIVE: The objective of this study was to assess the time of surgery as a possible predictor for outcomes, length of stay, and cost following microdiscectomy.

SUMMARY OF BACKGROUND DATA: The volume of microdiscectomy procedures has increased year over year, heightening interest in surgical outcomes. Previous investigations have demonstrated an association between time of procedures and clinical outcomes in various surgeries, however, no study has evaluated its influence on microdiscectomy.

METHODS: Demographic and outcome variables were collected from all patients that underwent a nonemergent microdiscectomy between 2008 and 2016. Patients were divided into 2 cohorts: those receiving surgery before 2 PM were assigned to the early group and those with procedures beginning after 2 PM were assigned to the late group. Outcomes and patient-level characteristics were compared using bivariate, multivariable logistic, and linear regression models. Adjusted length of stay and cost were coprimary outcomes. Secondary outcomes included operative complications, nonhome discharge, postoperative emergency department visits, or readmission rates.

RESULTS: Of the 1261 consecutive patients who met the inclusion criteria, 792 were assigned to the late group and 469 were assigned to the early group. There were no significant differences in demographics or baseline characteristics between the 2 cohorts. In the unadjusted analysis, mean length of stay was 1.80 (SD=1.82) days for the early group and 2.00 (SD=1.70) days for the late group (P=0.054). Mean direct cost for the early cohort was $5088 (SD=$4212) and $4986 (SD=$2988) for the late cohort (P=0.65). There was no difference in adjusted length of stay or direct cost. No statistically significant differences were found in operative complications, nonhome discharge, postoperative emergency department visits, or readmission rates between the 2 cohorts.

CONCLUSION: The study findings suggest that early compared with late surgery is not significantly predictive of surgical outcomes following microdiscectomy.