Morbidity and mortality of Alzheimer disease in Italy

Luisa Frova, Instituto Nazionale di Statistica (ISTAT)
Stefano Marchetti, Instituto Nazionale di Statistica (ISTAT)
Monica Pace, Instituto Nazionale di Statistica (ISTAT)
Alessandra Burgio, Instituto Nazionale di Statistica (ISTAT)

Background: Presence of co-morbidity is a typical feature of Alzheimer (AD) patients. Methods: Statistics on hospitalization and mortality were used to study trends of AD. Co-morbidity patterns were compared between the two sources for year 2003. The Italian register on hospital discharges was analysed for AD (1999-2004). The Italian data base on causes of death was analysed for AD (1985-2003). Analysis of multiple causes of death was performed for 2003. Results: Hospital discharges where AD is main diagnosis raised from 5,074 in 1999 to 10,900 in 2004. More than 90% of discharges for AD were referred to patients aged 65 and over. The hospital discharge standardized rate considering AD as main diagnosis increased from 44,07 to 87,48 per 100,000. By including also the secondary diagnosis the number of cases rises to 26,741 in 2003. For 39 discharges out of 100 AD was coded as main diagnosis. When AD is reported as main diagnosis in hospital discharges, the more frequently associated diseases to AD are ‘other mental disorders’, hypertensive diseases, cerebrovascular diseases and other diseases of the circulatory system. Deaths of AD increased from 296 cases in 1985 to 6,657 in 2003. Standardized rates per 100,000 for the deceased aged 65 and over increased from 3.32 in 1985 to 60.4 in 2003. The multiple causes of death analysis showed that AD was generally selected as underlying cause in 60.4% of deaths. Diseases of the circulatory system and diseases of the respiratory system are often jointly reported with AD both in mortality and in hospital discharges data. However for mortality, ill defined causes, pneumonia and influenza are frequently associated to AD. Conclusions: When the two data sources are compared, co-morbidity patterns are very similar, showing robust results.