1. Department of Population and Quantitative Health Sciences University of Massachusetts Chan Medical School Worcester Massachusetts USA
2. Department of Biostatistics and Epidemiology Graduate School of Public Health, Medical Sciences Campus, University of Puerto Rico San Juan Puerto Rico
3. Department of Restorative Sciences School of Dental Medicine, Medical Sciences Campus, University of Puerto Rico San Juan Puerto Rico
4. Division of Cancer Control and Population Sciences University of Puerto Rico Comprehensive Cancer Center San Juan Puerto Rico