Background

Some programs and insurers require patients undergo toxicology screening despite lack of evidence that this affects post-operative outcomes.

Methods

We performed a retrospective review of patients who underwent laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass from three institutions from 2017-2020. We describe the rate of pre-operative toxicology positivity as determined by serum and urine testing. We examine the association between toxicology positivity and outcomes of pre-operative length, 30-day complications (bleeding, venous thromboembolism, leak, wound infection, pneumonia, UTI, and myocardial infarction), readmissions, and weight loss using chi-square and t-test analysis.

Results

These results represent preliminary data from 200 patients (2017-2018). There were 38 patients (19%) who had positive toxicology testing. Of these, 3 (7.9%) were positive for nicotine and 11 (29%) for opiates. Pre-operative length was 369.2 days (SD 255.0) for patients with positive testing vs 297.9 days (SD 166.3, P=0.04) for negative. Chi-square testing demonstrated toxicology positivity was not associated with complications (10.5% for positive vs 4.3% for negative, X2=2.35, P=0.12) nor with readmissions (7.9% for positive vs 4.3% for negative, X2=0.86, P=0.35). There was no association between toxicology positivity and one-year weight loss: positive 95.4lbs lost (SD 51.9) vs negative 101.9lbs lost (SD 58.0, P=0.53).

Conclusions

Our study is the first to describe pre-operative toxicology positivity rates. We found no association between toxicology positivity and readmissions, complications, nor weight loss. Given its lack of impact on outcomes and increased delay to surgery, toxicology testing prior to bariatric surgery may be an unnecessary burden on patients and healthcare cost.