Bjornsdottir E, Janson C, Lindberg E, Arnardottir ES, Benediktsdottir B, Garcia-Aymerich J, Carsin AE, Real FG, Toren K, Heinrich J, Nowak D, Sanchez-Ramos JL, Demoly P, Arenas SD, Navarro RC, Schlunssen V, Raherison C, Jarvis DL, Gislason T. Respiratory symptoms are more common among short sleepers independent of obesity. BMJ Open Respir Res. 2017 Aug 30;4(1):e000206. doi: 10.1136/bmjresp-2017-000206
Groenwold RH, Klungel OH, Altman DJ, van der Graaf Y, Hoes AW, Moons KG, Rivero E, Fortuny J, PROTECT WP2. Adjustment for continuous confounders: an example of how to prevent residual confounding. Can Med Assoc J. 2013 Mar 19;185(5):401-6. doi: 10.1503/cmaj.120592
Huybrechts KF, Rothman KJ, Silliman RA, Brookhart MA, Schneeweiss S. Risk of death and hospital admission for major medical events after initiation of psychotropic medications in older adults admitted to nursing homes. Can Med Assoc J. 2011 Apr 1;183(7):E411-9.