Volume 8: Variant CJD
4. Work of the CJD Surveillance Unit
Development of the questionnaire

4.12 The questionnaire used by the CJDSU was based on the previous one developed by Dr Will in 1979 for his work with Professor Matthews. ¹ It included sections on patient's symptoms just prior to becoming ill (prodromal phase), past medical history, family history, social history (residential, occupation, diet), exposure to animals, clinical history, results of diagnostic investigation and case classification.

4.13 Minor changes were made to it before it was used in 1991 and subsequent alterations were made throughout the period 1991-95, as knowledge about CJD developed. After the identification of the variant form of CJD in 1996 and the possible link between this new form of CJD and BSE, substantial changes were made to the questionnaire, in an attempt to discover if indeed there was a causal link (see Annex 1 for the latest version). Table 4.1, below, describes the changes made.