PREDICTION OF CANCER AND CORONARY HEART-DISEASE AS A FUNCTION OF METHOD OF QUESTIONNAIRE ADMINISTRATION

We have tested the hypothesis in this study that different methods of administering a questionnaire produce differential approximations to t ruthful admission of undesirable personality traits and behaviours. Fo ur different methods of administration produced different levels of tr ust and understanding, using the current prediction among healthy subj ects of death by cancer or coronary heart disease 13 years later as th e criterion. There were significant differences in the accuracy of the predictions, depending crucially on the method of administration of t he questionnaires. Best predictions were achieved for subjects when bo th trust and understanding had been increased by interviewers' suitabl e participation; worst results were achieved for subjects when no spec ial effort was made to increase either. Intermediate results were foun d for procedures which increased either trust or understanding. It is argued that the success or failure of studies investigating the influe nce of personality and stress on diseases like cancer and coronary hea rt disease may depend crucially on the adopted method of interrogation .