Surveillance techniques for respiratory illness.

The data presented represent a pilot study to determine the most efficient method of detecting the frequency and severity of respiratory illnesses in a defined population of children. Home surveillance telephone calls, parent-completed diaries, and monitoring of school absence lists were used. Detailed questionnaires were used to investigate reported illnesses. No one method of surveillance provided accurate estimates of respiratory morbidity in young children, and physicians' records were not reliable enough to be used as the sole source for data validation. Use of multiple sources for surveillance, however, provided illness rates comparable to those obtained in other community surveillance programs.