Abstract
BACKGROUND: Nicotine dependence is one of the most significant barriers to smoking cessation. Therefore, measuring this dependence is crucial for effective smoking cessation interventions. The current study aimed to evaluate the degree of agreement between the Fagerström Test for Nicotine Dependence (FTND) and the Heaviness of Smoking Index (HSI) among Iranian smokers. METHODS: We analyzed the data obtained from two previous studies among 580 daily smokers in Iran. Data were collected using the FTND scale. Cohen's kappa was utilized to assess the degree of agreement between HSI and FTND. FINDINGS: The HSI showed significant agreement with FTND (Cohen's kappa=0.72) in assessing nicotine dependence, with a sensitivity of 88.6% and a specificity of 90.3%. CONCLUSION: The HSI is a valid and reliable tool for measuring nicotine dependence, exhibiting significant agreement with FTND. As a result, the HSI can be considered an alternative to the FTND in both clinical and research settings, particularly for heavy smokers.