1 CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru. Electronic address: antonio.bernabe@upch.pe.
2 CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru; Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK.