Prevalence of chronic diseases in older Italians: comparing self- reported and clinical diagnoses. The Italian Longitudinal Study on Aging Working Group
BACKGROUND: The Italian Longitudinal Study on Aging (ILSA) evaluates the rates of diabetes, cardiovascular and neurological disorders in a random sample of 5632 Italians aged 65-84 years. METHODS: The ILSA has two components: a first screening phase administered to all participants, that includes a personal interview, physician examination, laboratory and diagnostic tests, and a second phase, consisting of the clinical confirmation of suspected cases by a specialist. RESULTS: Prevalence rates were significantly higher among men for myocardial infarction (10.7% versus 4.8%), cardiac arrhythmia (25.1% versus 20.3%) and peripheral artery disease (8.1% versus 5.2%), and among women for hypertension (67.3% versus 59.4%), heart failure (7.3% versus 5.4%) and dementia (7.2% versus 5.3%). No gender difference was found for stroke, angina, diabetes, Parkinsonism and distal symmetric neuropathy. Unreported diagnoses accounted for 85% of cases of distal symmetric neuropathy, for more than half the cases of cardiac failure, for 40% of cases of angina, and for more than one-third of cases arrhythmia, myocardial infarction, peripheral artery disease, hypertension, Parkinsonism. Data from the phase 1 interview showed substantial overreporting for myocardial infarction, peripheral artery disease, diabetes, and stroke. CONCLUSIONS: The authors conclude that self-reported information would lead to inaccurate estimates of prevalence rates suggesting the need for including the clinical ascertainment in any population-based epidemiological study.