A comparison of responses to a health and lifestyle questionnaire completed before and then after blood pressure screening

Changes over a 2-week period in self-reported health and lifestyle information were examined and related to medical feedback provided prior to the second self-report. The study group consisted of 128 females and 73 males ranging in age from 35 to 85 with a mean age of 55.5 years. On two occasions subjects completed self-assessment questionnaires including 52 items covering symptamatology and various lifestyle behaviours. Before the second self-assessment, subjects were classified as cases if their blood pressure was borderline or hypertensive according to World Health Organization guidelines or as controls otherwise. Subjects were informed of this classification. Across questions, the percentage disagreement between reports ranged from 0.0% to 44.1% with a median of 17.5% and with case-control differences significant at the 10% level for four questions. The mean difference between responses was significantly different from 0 at the 10% level for 15 questions with case-control differences significant at the 10% level for 6 questions. For 2 questions, the significance level of the association of response with case-control status changed from a value greater than 20% based on responses before feedback to a value less than 5% based on responses after feedback. Some evidence of recall bias was found.