Cotinine Testing Improves Smoking Cessation Before Total Joint Arthroplasty

Patients who are actively smoking at the time of primary total joint arthroplasty (TJA) are at an increased risk of perioperative complications. Serum cotinine testing is a sensitive and specific method to verify abstinence from smoking and may therefore improve a patient's chance of smoking cessation. The primary purpose of this study was to assess whether cotinine testing improves the self-reported quit rate among smokers before TJA.

Our hospital performs a high volume of TJAs and documents smoking status at each clinic visit (at 6-month intervals), as well as at the time of surgery through an institutional total joint registry. As part of a retrospective analysis, this information was used to identify all self-reported smokers (regularly cigarette smoking within 1 year of TJA) who underwent unilateral TJA from 2007 to 2018. The cohort had a mean age of 66 years, 55% were female, and the mean body mass index was 31 kg/m². Patients whose serum cotinine was obtained within 1 month before surgery were then separated from the cohort and compared to the smokers who did not undergo cotinine testing.

Of the 28,758 primary TJAs identified, 8.8% (2514) were smokers. Serum cotinine testing was obtained on 103 of these patients. The abstinence rate (by means of self-reporting) before surgery significantly improved from 15.8% to 28.2% in the untested vs cotinine-tested groups, respectively (P = .005). Among all patients who underwent cotinine testing, 77% were negative (abstinent) and an additional 15% had cotinine levels between 3 and 8 ng/mL representing passive tobacco exposure. Among patients who stated they had quit smoking, 15% still had positive cotinine tests.

Smoking cessation remains a major challenge in contemporary TJA practices despite a concerted effort to help patients quit. Our findings suggest that cotinine testing significantly improves the self-reported quit rates of smokers before surgery and helps identify the 15% who falsely report abstinence to ensure appropriate counseling of inherent risks.

Therapeutic level III.