Epilepsy in a Longitudinal Survey of 5,000 Children

This paper records some of the findings concerning different types of epilepsy in a longitudinal study of approximately 5,000 children born in 1946. These children form the National Survey of Health and Development which has been described previously (Douglas and Rowntree, 1948 ; Douglas and Blomfield, 1956). The children are drawn from all parts of Great Britain and from all social classes, and have been kept under observation from their birth in March 1946 to the present. Apart from death and emigration, losses from the survey have been small, and at the age of 15 years were approximately 10% (for details of the survey method and losses see Douglas and Blomfield (1958), and Douglas (1964) ). During the 18 years of their lives a large amount of social, medical, and educational information has been gathered about each child, and the medical information referred to in this paper comes mainly from : (1) A home visit by a health visitor when the child was aged 2 years. The mother was asked if the child had ever had any sort of fit or convulsion, and if so, at what age and how many. She was also asked in detail about illnesses such as whooping-cough, measles, ear disease, chicken-pox, gastro-enteritis, and lower respiratory infections. (2) Medical examinations carried out specially for this survey by school medical officers at the ages of 6, 7, 11, and 15. The mothers, who accompanied the children, were asked if their child had had any sort of fits or convulsions in the previous year, and if so, how many and whether they had accompanied any other illness. In this report the definition of a fit is a definite reply of yes recorded by the doctor or the health visitor after asking these questions. The doctor was at liberty to ask other questions to clarify the mother's reply, and the extent of additional probing would obviously vary. In a widespread survey such as this, however, there was no way of avoiding this sort of variation.