Trends in childhood disability.

This article summarizes and analyzes possible explanations for the near doubling, since 1960, of the proportion of children with limitations of activity due to chronic illness as reported in the National Health Interview Survey (NHIS). We examine several possible explanations for the upward trend in prevalence including: changes in survey design and procedures; changes in awareness of chronic illness on the part of parents and physicians; and changes in the institutionalized population of disabled children. Our analysis indicates that only a small part of the trend can be explained directly by these factors. Further examination of the NHIS data reveals that the types of limitations of activities now reported are less likely to cause frequent confinement in bed; whether this indicates lesser severity or principally different types of chronic conditions is as yet unclear.