The elderly at home: indices of disability.

The physical status of all people aged 75 and over living in and around Melton Mowbray was assessed by the responses to a series of questions on the activities of daily living that the respondents could perform. Three methods of producing an index of disability from these separate questions are investigated: principal component analysis, Guttman scaling, and a variation of Guttman scaling known as severity grading. All the methods produced very similar rankings of persons, confirming the suggestion of Bebbington that the choice of scaling method is of little consequence. Two scales emerged: one measuring physical ability and the other the level of urinary and faecal incontinence.