1. Dermatology, Medicine; Department of Public Health and Clinical Medicine; Umeå University Umeå; Umeå Sweden
2. Industrial Doctoral School; Umeå University; Umeå Sweden
3. Karolinska Institutet; Centre for Pharmacoepidemiology; Solna Sweden
4. Department of Statistics; Umeå School of Business and Economics; Umeå University; Umeå Sweden