The association between nicotine dependence and sleep quality in patients referred to a smoking cessation outpatient clinic: A cross-sectional study.

Introduction: Nicotine addiction is one of the most common forms of dependence. It is shown to be associated with many chronic diseases that develop mostly through smoking. The association between sleep quality and smoking or nicotine addiction has not been clarified yet. This study aimed to investigate the association between nicotine addiction and sleep quality.

Methods: In this cross-sectional study, the Epworth sleepiness scale (ESS), Pittsburgh sleep quality index (PSQI), Fagerström test for nicotine dependence (FTND), and Hospital anxiety-depression scale (HADS) were administered to patients who applied to the smoking cessation outpatient clinic of a reference hospital between April and June 2023. FTND measured nicotine dependence, and its association with sleep quality estimated by PSQI was assessed by binary logistic regression with the potential confounders.

Results: In the study group of 280 participants, 67.1% were male, and 57.8% had poor sleep quality. The median (IQR) FNTD score was 7.0 (3.0), and the median global PSQI score was 6.0 (5.0). Poor sleep quality increased by 1.12 times (AOR=1.12; 95% CI: 1.02-1.22, p=0.016) for each unit increase in hospital anxiety score and by 1.22 times (AOR=1.22; 95% CI: 1.05-1.42, p=0.011) for each unit increase in FTND score.

Conclusions: Increased nicotine dependence and anxiety are independently associated with poor sleep quality. The findings support smoking cessation efforts. It is recommended to study the effect of combating anxiety and tobacco addiction to improve sleep quality.