1. Ekman M, Johnell O, Lidgren L. The economic cost of low back pain in Sweden in 2001. Acta Orthop. 2005;76:275–84.
2. Mortensen OS, Andersen JH, Ektor-Andersen J, Eriksen HR, Fallentin N, Frost P, et al. White paper on sickness absence and return-to-work due to musculoskeletal disorders – causes and options [in Danish]. Copenhagen: National Research Centre for the working environment; 2008.
3. The Norwegian Labour and Welfare Administration (NAV). Statistics on certified sickness absence 2017 [in Norwegian].
https://www.nav.no/no/NAV+og+samfunn/Statistikk/Sykefravar+-+statistikk/Tabeller/legemeldte-sykefrav%C3%A6rsdagsverk-2-kv-2008-2017-diagnose-og-kj%C3%B8nn
. Acceessed 22 Dec 2018.
4. Welsh VK, Mallen CD, Wynne-Jones G, Jinks C. Exploration of GPs' views and use of the fit note: a qualitative study in primary care. Br J Gen Pract. 2012;62:e363–70.
5. King O, Nancarrow SA, Borthwick AM, Grace S. Contested professional role boundaries in health care: a systematic review of the literature. J Foot Ankle Res. 2015;8:2.