Care continuity across levels of care perceived by patients with chronic conditions in six Latin-American countries oleh Laia Ollé-Espluga, Ingrid Vargas, Amparo Mogollón-Pérez, Renata-Patricia Freitas Soares-de-Jesus, Pamela Eguiguren, Angélica-Ivonne Cisneros, María-Cecilia Muruaga, Adriana Huerta, Fernando Bertolotto, María-Luisa Vázquez