Effectiveness of Motivational Interviewing by Nurses on Smoking Cessation Among Male Adult Patients in General Hospitals in Oyo State

Background: Tobacco smoking remains a significant modifiable risk factor for non-communicable diseases in Nigeria. Motivational interviewing is an evidence-based behavioural intervention that nurses are positioned to deliver within routine clinical encounters. Aim: This study assessed the effectiveness of nurse-delivered motivational interviewing on smoking cessation among male adult patients at general hospitals in Oyo State, South West Nigeria. Methods: A randomised controlled trial allocated 120 male current smokers attending outpatient clinics to motivational interviewing and brief advice comparison groups over 12 weeks. Smoking cessation self-report and cotinine validation were the primary outcomes. Logistic regression analysis assessed group differences. Results: At three months, the motivational interviewing group had significantly higher quit rates at 34% compared with 14% in the brief advice group (OR = 3.18, p = 0.002). Sustained quit rates at six months were 27% and 9% respectively. Conclusion: Nurse-delivered motivational interviewing is an effective, scalable smoking cessation strategy in Nigerian outpatient settings. The study supports embedding motivational interviewing training in nursing education and clinical practice guidelines. Keywords: motivational interviewing, smoking cessation, nurses, Oyo State, tobacco.