1. Department of Epidemiology and Biostatistics; Norman J. Arnold School of Public Health; University of South Carolina; Columbia SC USA
2. Department of Community Medicine and Behavioral Sciences; Faculty of Medicine; Kuwait University; Safat Kuwait
3. Division of Epidemiology, Biostatistics, and Environmental Health; School of Public Health; University of Memphis; Memphis TN USA
4. Academic Units of Clinical and Experimental Medicine; University of Southampton; Southampton UK
5. Human Development and Health; Faculty of Medicine; University of Southampton; Southampton UK
6. College of Veterinary Medicine; Michigan State University; East Lansing MI USA
7. David Hide Asthma and Allergy Research Centre; Isle of Wight UK