The object of the study is to investigate the (in)accuracy of patients' self-reports, as compared with general practitioners' information, regarding the presence of specific chronic diseases, and the influence of patient characteristics. Questionnaire data of 2380 community-dwelling elderly patients, aged 55-85 years, on the presence of chronic non-specific lung disease, cardiac disease, peripheral atherosclerosis, stroke, diabetes, malignancies, and osteoarthritis/rheumatoid arthritis were compared with data from the general practitioners, using the kappa-statistic. Associations between the accuracy of self-reports and patient characteristics were studied by multiple logistic regression analyses. Kappa's ranged from 0.30 to 0.40 for osteoarthritis/rheumatoid arthritis and atherosclerosis, to 0.85 for diabetes mellitus. In the multivariate analyses, educational level, level of urbanization, deviations in cognitive function, and depressive symptomatology had no influence on the level of accuracy. An influence of gender, age, mobility limitations, and recent contact with the general practitioner was shown for specific diseases. For chronic non-specific lung disease, both "underreporting" and "overreporting" are more prevalent in males, compared to females. Furthermore, males tend to overreport stroke and underreport malignancies and arthritis, whereas females tend to overreport malignancies and arthritis. Both overreporting and underreporting of cardiac disease are more prevalent as people are older. Also, older age is associated with overreporting of stroke, and with underreporting of arthritis. The self-reported presence of mobility limitations is associated with overreporting of all specific diseases studied, except for diabetes mellitus, and its absence is associated with underreporting, except for diabetes mellitus and atherosclerosis. Recent contact with the general practitioner is associated with overreporting of cardiac disease, atherosclerosis, malignancies and arthritis, and with less frequent underreporting of diabetes and arthritis. Results suggest that patients' self-reports on selected chronic diseases are fairly accurate, with the exceptions of atherosclerosis and arthritis. The associations found with certain patient characteristics may be explained by the tendency of patients to label symptoms, denial by the patient, or inaccuracy of medical records.
