Key points from article :
Vaping among young people increased by 900 % between 2011 and 2015.
Researchers gathered data on over 400,000 participants, 66,800 of whom used e-cigarettes.
People who use e-cigarettes have a 71 % higher risk of stroke, 40 % higher risk of heart disease.
This study is a call for larger and longer studies into e-cigarettes issue.
