Waterpipe tobacco smoking and cigarette equivalence

The authors of this editorial¹ on shisha (waterpipe) guidance tentatively offer 10 cigarettes as equivalent to a shisha session of 45 minutes. In our freely available smoking pack year calculator on the web² we have taken guidance from a World Health Organization study on waterpipe smoking.³ From this study an 80-minute session of such smoking was compared with 100 cigarettes and thus a 45-minute session would be around 60 cigarettes equivalence. As shisha smokers can use in both personal and group settings we have used a 20-minute session (25 cigarette equivalence) as our baseline in the calculator. Of course this is simply an approximation but hopefully helpful to all the health staff who need to calculate smoking pack years. Smoking pack years is a figure that combines smoking duration and smoking intensity, and one smoking pack year is defined as 20 cigarettes smoked daily for 1 year.