Main outcomes at twelve months.

SD = Standard deviation.P* Tobacco only vs electronic cigarettes only** Tobacco only vs both tobacco and electronic cigarettes (dual smoking)*** E-cigarettes only vs both tobacco and electronic cigarettes (dual smoking).€ EuroQol final item, ranging from 1 (feel very bad) to 10 (perfectly healthy).ψ Chronic obstructive pulmonary diseases, stroke, heart failure, myocardial infarction, angina, pneumonia, cancer of: larynx or oral cavity, lung, stomach, pancreas, cervix, kidney, bladder, myeloid leukaemia.Main outcomes at twelve months.