Asking pre-operative patients to opt out of referral to Stop Smoking Services via Short Message Service: A controlled interrupted time series analysis.

Abstract

Background and aims: Smoking tobacco increases the risk of intra- and post-operative complications. Abstinence before surgery reduces these risks and costs to healthcare services. This study measured smoking abstinence among elective pre-operative patients who smoked following a modified clinical pathway. Design: An observational, follow-up study of patients who received the changed pre-operative pathway, supplemented by a controlled interrupted time series analysis (ITSA) of hospital patients referred to the community Stop Smoking Service (SSS) between April 2020 and August 2024. Patients referred to the SSS by primary care clinicians acted as a negative control to assess whether any observed changes reflected general time trends rather than the intervention effect. Setting: A district general hospital in Nottinghamshire, United Kingdom, during January 2024. Participants: 476 pre-operative patients recorded as smokers in primary care electronic health records (52% female; mean age 52 years) awaiting elective procedures taking place in more than 6 weeks were included. Intervention: Patients who had completed the routine pre-operative care pathway were invited via Short Message Service message (SMS) to opt out of SSS referral. Those who did not respond within 14 days were referred. The SSS provided usual care consisting of face-to-face or virtual counselling and an offer of nicotine replacement therapy. The intervention was low-cost and used existing pre-operative services. Measurements: The primary outcome was patient-reported smoking abstinence 28 days after an agreed quit date. This is a routinely collected SSS outcome. Controlled ITSA compared weekly counts of first SSS appointments between secondary care and primary care referrals among patients who subsequently achieved abstinence, before and after the intervention was implemented. Findings: 10.5% (50/476) of patients reported 28-day abstinence. 25.4% (121/476) booked an SSS appointment and 16% (77/476) opted out of SSS referral. 63.9% (304/476) were contactable by the SSS and 54.2% (258/476) confirmed smoking. 19.4% (50/258) of patients who were contactable and confirmed smoking stopped. ITSA indicated an immediate increase in weekly hospital patients referred who reported abstinence was not due to any general time trends (5.83, 95% confidence interval = 2.50-9.16, P < 0.001), consistent with a pulsed intervention of limited duration. Conclusions: Inviting elective surgical patients to opt out of Stop Smoking Service referral via Short Message Service message appears to increase 28-day smoking abstinence.