1. Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Division of Orthopedics, Karolinska University Hospital, Sweden
2. Clinical Epidemiology Unit, Department of Medicine, Solna, Karolinska Institutet, Sweden
3. Center for Pharmacoepidemiology, Department of Medicine, Solna, Karolinska Institutet, Sweden
4. Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran