Cannabis Abuse or Dependence and Post-operative Outcomes After Appendectomy and Cholecystectomy

Though cannabis is gaining broader acceptance among society and a noted increase in legalization, little is known regarding its impact on post-operative outcomes. We conducted this study to quantify the relationship between cannabis abuse or dependence (CbAD) on post-operative outcomes after cholecystectomy and appendectomy.

Using the 2013-2015 Nationwide Readmissions Database, we identified discharges associated with cholecystectomy or appendectomy from January 2013-August 2015. Patients were grouped by CbAD history. The primary outcomes were length of stay, serious adverse events, home discharge, and 30-day readmission. Propensity-score matching was used to account for differences between groups and all statistics accounted for the matched sample.

The final sample included 3288 patients with a CbAD history matched 1:1 to patients without a CbAD history (total sample = 6576). After matching, acceptable balance was achieved in clinical characteristics between groups. In the cholecystectomy cohort (n = 1707 pairs), CbAD patients had longer hospitalizations (3.5 versus 3.2 d, P 0.003) and similar rates of serious adverse events (6.1 versus 4.8, P 0.092), home discharge (96.1 vs 96.2, P 0.855), and readmission (8.3 versus 6.9, P 0.137). In the appendectomy cohort (n = 1581 pairs), CbAD patients had longer hospital stays (2.7 versus 2.5 d, P 0.024); more frequent serious adverse events (5.0 versus 3.5, P 0.041); and similar home discharge (96.8 vs 97.3, P 0.404) and readmission (5.4 versus 5.1, P 0.639) rates.

Patients with a history of CbAD in the cholecystectomy and appendectomy cohorts had slightly longer hospital stays, and patients with a history of CbAD in the appendectomy group displayed a slight increase in adverse events, but otherwise similar clinical outcomes without clinically significant increases in complications compared to patients without this history.