1. Department of Community Health, School of Medicine, Federal University of Ceará, Fortaleza, Brazil.
2. Department of Nursing, Federal University of Ceará, Fortaleza, Brazil.
3. Department of Statistics and Applied Mathematics, Federal University of Ceará, Fortaleza, Brazil.
4. Nucleus for Population Studies, State University of Campinas, Brazil.
5. Institute for Collective Health, Federal University of Bahia, Brazil.
6. Department of International Health and Development, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana.