COMMON HEALTHCARE VISITS PRIOR TO THE DIAGNOSIS OF DEMENTIA

Background Dementia is commonly associated with co-morbidities and non-specific presentations. Individualised dementia care should ideally be provided within the context of these co-morbidities and presentations. To provide systematic insights, we described the dynamic changes of 20 commonest healthcare visits prior to the diagnosis dementia in Taiwan. Methods We adopted a nested case-control approach. From the Taiwanese healthcare records, which covers >99% of Taiwanese population, we identified 491,000 case individuals first diagnosed to have dementia after age 50 years during 2002–2015, and control individuals matched at 1:1 ratio by age, sex, year of birth, and region at the time of first diagnosis. By 3-digit codes according to the International Classification of Diseases, 9th Edition (ICD-9), we identified 20 commonest causes of healthcare visits in case individuals between 2000 and 2015. Using stratified Poisson regression, we estimated cause-specific rates of healthcare visits between cases and controls within a compatible person-year, and observed the change of relative rates over the 8-year span leading to the diagnosis of dementia. With the large sample size, confidence of intervals of these relative rates for common events were almost negligible. Results There was gradual increase in average numbers of all-cause healthcare visits prior to the diagnosis of dementia. However, we observed various decline of 15 of 20 cause-specific care prior to the diagnosis of dementia compared to controls, including diabetes mellitus (ICD-9 250), disorders of lipid metabolism (ICD-9 272), cataract (ICD-9 366), disorders of conjunctiva (ICD-9 372), essential hypertension (ICD-9 401), other form of chronic ischaemic heart disease (ICD-9 414), acute nasopharyngitis (ICD-9 460), acute upper respiratory infections of multiple or unspecific sites (ICD-9 465), acute bronchitis and bronchiolitis (ICD-9 466), diseases of hard tissues of teeth (ICD-9 521), and gingival and periodontal diseases (ICD-9 522), gastritis and duodenitis (ICD-9 535), osteo-arthrosis and allied disorders (ICD-9 715), other and unspecified disorders of back (ICD-9 724), and other disorders of soft tissues (ICD-9 729). Four causes of healthcare visits that increased prior to the diagnosis of dementia included neurotic disorders (ICD-9 300), disorders of function of stomach (ICD-9 536) functional digestive disorders, not elsewhere specified (ICD-9 564), and possibly contact dermatitis and other eczema (ICD-9 692). There was little change in hypertensive heart disease (ICD-9 401 prior to the diagnosis of dementia) Conclusion Paradoxical to the increase in all-cause healthcare visits prior to the diagnosis of dementia, there was decline of commonest care prior to the diagnosis of dementia. The few increasing exceptions could be common presentations prior to the diagnosis of dementia. These time-dependent findings provide systematic insights into dementia care and diagnosis.