Assessing the Italian version of the respiratory symptom experience scale (IT-RSES) in smokers and former smokers: a...

Smoking causes respiratory symptoms, and research suggests these improve with cessation or switching to less harmful nicotine products. The Respiratory Symptom Experience Scale (RSES) was developed and validated for the purpose of assessing these such symptoms online in an English-speaking American sample. This study aimed to develop and validate an Italian version, the IT-RSES, administered via telephone interview, and, further, to use it to assess symptoms in smokers who had switched to e-cigarettes or to heated tobacco products (HTPs).

After translation into Italian, the IT-RSES was administered by phone interview to 750 Italian participants in 5 tobacco use groups (150 each never-smokers, former smokers not using alternative products, HTP users, e-cigarette users, and continuing smokers) who also reported any history of diagnoses with relevant medical conditions. Psychometric analyses examined scale factor structure, reliability, and convergent validity. Analyses controlling for age and for years smoking compared symptoms across tobacco use groups.

Factor analyses confirmed the IT-RSES' unidimensionality (factor one accounting for 74.2% of the variance; all factor loadings > 0.80). Internal-consistency reliability was high ( Cronbach's alpha = 0.91). IT-RSES scores correlated significantly with years of smoking (r = 0.51, p < 0.0001), and were higher in individuals with respiratory conditions (2.02 vs. 1.36, SE = 0.05, significant by THSD). Discriminant validity was demonstrated by higher scores in smokers compared to never-smokers, even among those without respiratory conditions. After adjustment for years of smoking, former smokers, HTP users and e-cigarette users had lower scores than smokers (m = 2.17 vs. 1.49, SE = 0.06, p < 0.05, THSD; 1.63 vs. 2.16, SE = 0.06, THSD) and did not significantly differ from each other.

The results support the reliability and validity of the IT-RSES, suggesting its utility for assessing respiratory symptoms in smokers, and former smoker who stopped smoking and were using e-cigarettes or HTPs. The scores of former smokers are similar to those not using these products, and lower than smokers', suggests that HTPs and e-cigarettes do not add materially to respiratory symptoms when smokers stop smoking.