%0 Journal Article %J BMC Public Health %D 2020 %T General practice patients starting treatment for substance use problems: observations from two data sources across levels of care %A Nicole Boffin %A Jérôme Antoine %A L Van Baelen %A S Moreels %A Kris Doggen %B BMC Public Health %V 20 %8 Jan-12-2020 %G eng %N 1 %R 10.1186/s12889-020-09038-0