Background:
Waterpipe smoking originated in the Eastern Mediterranean region. It is highly prevalent among university students, and has been increasing in popularity despite mounting evidence showing it is harmful to health. The aim of this study was to measure preferences for waterpipe smoking and determine which product characteristics are most important to smokers.

Methods:
Participants in 5 countries (Egypt, Jordan, Oman, Palestine, and UAE) completed an Internet-based discrete choice experiment to reveal their preferences for, and trade-offs between, the attributes of hypothetical waterpipe smoking sessions. Participants were presented with waterpipe lounge menus, each with 6 fruit-flavored options and 1 tobacco flavored option, in addition to an opt out option. Participants were randomized to either receive menus with a pictorial+text health-warning message or no message. Multinomial and nested logit models were used to estimate the impact on consumer choice of attributes and between-subject assignment of health warnings respectively.

Results:
On average, participants preferred fruit-flavored varieties to tobacco flavor. They were averse to options labelled with higher nicotine content. Females and non-smokers of cigarettes were more likely than their counterparts to prefer flavored and nicotine-free varieties. Participants exposed to a health warning were more likely to opt out.

Conclusions:
Fruit-flavored tobacco and lower nicotine content labels, two strategies widely used by the industry, increase the demand for waterpipe smoking among young adults. Waterpipe-specific regulation should limit the availability of flavored waterpipe tobacco and require accurate labelling of constituents. Waterpipe-specific tobacco control regulation, along with research to inform policy, is required to curb this emerging public health threat.