Could the use of biochemical validation of smoking abstinence introduce a confound into the interpretation of randomized controlled trials of tobacco cessation?

Cunningham, JohnKushnir, Vladyslav2015-12-102015-12-100965-2140http://hdl.handle.net/1885/54242Could the use of biochemical validation of smoking abstinence introduce a confound into the interpretation of randomized controlled trials of tobacco cessation?201310.1111/add.121112015-12-09