Tobacco Exposure and Influencing Factors of Smoking Cessation Among Chronic Kidney Disease Patients

The Fagerstrom Test for Nicotine Dependence (FTND) was applied to assess nicotine dependence, which has a set of 6 items with an overall score ranging from 0-10. High dependence was defined as an FTND score ≥7; medium dependence, a score ranging from 4-6; low dependence, a score ranging from 0-3.

Knowledge of health hazards of active and passive smoking was applied to assess perceptions of tobacco harm. The questionnaire has a set of 17 items which was developed according to the literature review content. Participants were asked to answer whether the knowledge about tobacco harm contained in the entry is correct: yes, no, or don't know. the higher percentages of correct responses to each item of the knowledge subscale means the better mastery of self-awareness of the hazard of smoking.

Tobacco-related chronic kidney disease (CKD) was applied to assess knowledge of tobacco-related diseases. The questionnaire has a set of 23 items which was developed according to the literature review content (The delphi method was used to construct this knowledge level questionnaire). This questionnaire was categorized into three subscales, namely cigarette smoking increases the risk of CKD (15 items), e-cigarettes and nephrotoxicity (2 items) and health benefits of smoking cessation for patients with CKD (6 items), with the answer: know, know a little, do not know or not sure. Higher scores of both subscales indicate the greater mastery of knowledge of tobacco-related diseases.

Smoking Rationalization Beliefs (SRBs) refer to the relevant attitudes that smokers use to rationalize their smoking behavior and maintain their smoking status. The simplification of the scale with 8 items, each question use a five-point likert scale with 1 being 'strongly agree' and 5 being 'strongly disagree'. The higher the score was, the lower the SRBs.

Smoking Self-Efficacy Questionnaire (SEQ-12) was applied to assess the self-efficacy level. The SEQ-12 is a self-report inventory consisting of 12 items measuring the confidence of current and exsmokers in their ability to abstain from smoking in high-risk situations. The instrument is intended to measure two dimensions: internal stimuli (6 items) and external stimuli (6 items). Responses were solicited with a five-point Likert scale ranging from 1=not at all sure to 5=absolutely sure, where greater values indicated that the respondent perceived greater confidence in resisting smoking in the context.

The 9-item version of Minnesota Nicotine Withdrawal Scale (MNWS) was used for detection of withdrawal symptoms, which was revealed to have two domains of negative affect and insomnia and three individual items. Participants rated the symptoms by using a 5-point Likert-type (0=not present to 4=severe). Higher values of the MNWS indicate more severe nicotine withdrawal symptoms.