1. Faculty of Medicine, University of Medicine, Rr. “Dibres”, No. 371, Tirana, Albania
2. Institute of Public Health, Rr. "Aleksander Moisiu", No. 80, Tirana, Albania
3. Imperial Clinical Trials Unit, Imperial College London, Stadium House, 68 Wood Lane, London W12 7RH, UK
4. Department of Primary Care and Public Health, Imperial College London, St Dunstan’s Road, London W6 8RP, UK
5. Department of International Health, School CAPHRI (Care and Public Health Research Institute), Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands