Correlates of delayed referral for the diagnosis of dementia in an outpatient population.

ABSTRACT

BACKGROUND: Early diagnosis of dementia is critical, but there is usually a time lag between onset of symptoms and referral for neuropsychological testing and dementia diagnosis. We aimed to identify factors correlated with this delayed referral. METHODS: We studied 140 patients with cognitive deterioration referred to the Memory Clinic of the Catholic University (Rome) between 1995 and 1996. Alzheimer's disease or multi-infarct dementia was diagnosed according to National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria and Hachinski ischemic score. Global cognitive and neuropsychological functions were assessed with the Mini-Mental State Exam (MMSE) and the Mental Deterioration Battery. The performance on the Activities of Daily Living was used to measure physical function. The time between onset of signs of cognitive deterioration and referral for diagnosis (time to diagnosis TTD) was estimated through a semistructured interview of the caregiver. Independent correlates of TTD were identified after adjustment for potential confounders and stratifying patients based on level of physical function. RESULTS: Of 127 eligible patients, 63% had Alzheimer's disease, 26% multi-infarct dementia, and 11% had dementia of other types. Mean age was 73.9 +/- 8.2 years, and 59% of patients were females. The mean TTD was 13.8 +/- 10.8 months and did not differ by gender, household composition, or type of dementia. For patients with normal physical function, increased age (beta = .50), female sex (beta = .51), and low MMSE score (beta = .36) were associated with longer TTD. Among patients with physical impairment, only MMSE score showed an association with TTD, but it was of opposite direction (beta = -.31). These associations were consistent by type of dementia. CONCLUSIONS: Age, gender, and degree of cognitive impairment are important correlates of the time between onset of signs/symptoms and referral for dementia diagnosis. These factors are independent of the type of dementia but are influenced by the level of physical function.