RESUMEN
OBJECTIVE: To analyze the trend in hospitalization rates for ambulatory care sensitive respiratory diseases (ACSRD) of children under five years of age in Brazil. DESIGN: Time series study of hospitalization rates using secondary information from the Hospital Information System of the Brazil's Unified Health System. SAMPLE: Hospitalizations of children under five years of age living in Brazilian regions. Hospitalizations were separated according to cause: nose and throat infections, asthma, bacterial pneumonias, and lung diseases. MEASUREMENTS: Rates were calculated for total hospitalizations for ACSRD, and by cause, age group, and region. Trends were analyzed by using means of simple linear regression and were classified into stationary (p ≥ .05), ascending (ß positive and p < .05) or declining (ß negative and p < .05) trends. RESULTS: All regions showed stationary trends in total hospitalization rates for ACSRDs, except in the Southeast, where trends were ascending. Asthma was the only cause that showed a declining trend. Bacterial pneumonias showed stationary trends, while lung diseases and nose and throat infections had predominantly ascending trends. CONCLUSION: Brazil's hospitalization rates for ACSRDs are high. Investigations into primary health care organization and work processes, as well as socioeconomic, cultural, and geographical factors are necessary.