Self-report of chronic diseases in old-aged individuals: extent of agreement with general practitioner medical records in the German AugUR study

Abstract

Background: To estimate prevalence and incidence of diseases through self-reports in observational studies, it is important to understand the accuracy of participant reports. We aimed to quantify the agreement of self-reported and general practitioner-reported diseases in an old-aged population and to identify socio-demographic determinants of agreement.

Methods: This analysis was conducted as part of the AugUR study (n=2449), a prospective population-based cohort study in individuals aged 70-95 years, including 2321 participants with consent to contact physicians. Self-reported chronic diseases of participants were compared with medical data provided by their respective general practitioners (n=589, response rate=25.4%). We derived overall agreement, over-reporting/under-reporting, and Cohen's kappa and used logistic regression to evaluate the dependency of agreement on participants' sociodemographic characteristics.

Results: Among the 589 participants (53.1% women), 96.9% reported at least one of the evaluated chronic diseases. Overall agreement was >80% for hypertension, diabetes, myocardial infarction, stroke, cancer, asthma, bronchitis/chronic obstructive pulmonary disease and rheumatoid arthritis, but lower for heart failure, kidney disease and arthrosis. Cohen's kappa was highest for diabetes and cancer and lowest for heart failure, musculoskeletal, kidney and lung diseases. Sex was the primary determinant of agreement on stroke, kidney disease, cancer and rheumatoid arthritis. Agreement for myocardial infarction and stroke was most compromised by older age and for cancer by lower educational level.

Conclusion: Self-reports may be an effective tool to assess diabetes and cancer in observational studies in the old and very old aged. In contrast, self-reports on heart failure, musculoskeletal, kidney or lung diseases may be substantially imprecise.

Keywords: AGING; EPIDEMIOLOGY; GENERAL PRACTICE; GERIATRICS; HEALTH STATUS.

Figure 1

Overview of AugUR study recruitment with number of participants at baseline and in the general practitioner (GP) sub-study. Net response at baseline was 18.1%. For the GP sub-study, 36.7% of GPs responded, resulting in 25.4% of eligible AugUR participants. AugUR; Altersbezogene Untersuchungen zur Gesundheit der Universität Regensburg.

Figure 2

Cross-table and terms used for analysing agreement. A template cross-table is exemplified (top left). The rows show the positive and negative self-reports, the columns show the positive and negative GP reports. Also shown are terms used for analysing agreement, including the formula used to calculate Cohen’s kappa. Overall agreement, positive agreement, negative agreement, underreporters and overreporters are further used as percentage by multiplication of the depicted terms by factor 100. GP, general practitioner.