Influence of weekday of admission and level of distress on length of hospital stay in patients with low back pain: a retrospective cohort study oleh Emanuel Brunner, André Meichtry, Davy Vancampfort, Reinhard Imoberdorf, David Gisi, Wim Dankaerts, Anita Graf, Stefanie Wipf Rebsamen, Daniela Suter, Lukas Martin Wildi, Stefan Buechi, Cornel Sieber