Evidence also suggested that nicotine e-cigarettes led to higher quit rates than e-cigarettes without nicotine, or no stop smoking intervention, but less data contributed to these analyses. Data from the review showed that if six in 100 people quit by using nicotine replacement therapy, eight to twelve would quit by using electronic cigarettes containing nicotine. This means an additional two to six people in 100 could potentially quit smoking with nicotine containing electronic cigarettes. In studies comparing nicotine e-cigarettes to nicotine replacement treatment, significant side effects were rare. In the short-to-medium term (up to two years), nicotine e-cigarettes most typically caused throat or mouth irritation, headache, cough, and feeling nauseous.
