Higher quality of care and less surgery after implementing osteoarthritis guidelines in primary care - long-term results from a cluster-randomized controlled trial. Issue 1 (April 2020) - Østerås, N.; Moseng, T.; van Bodegom-Vos, L.; Dziedzic, K.; Andreassen, Ø.; Fenstad, A.; Furnes, O.; Hansen, J.N.; Natvig, B.; Røtterud, J.; Schjervheim, U.-B.; Vlieland, T.; et al.