Rates of formal diagnosis in people screened positive for dementia in primary care: results of the DelpHi-Trial.

BACKGROUND Primary data about rates of formal diagnosis of dementia in the German primary care sector are widely lacking. OBJECTIVES Main objectives are to analyze the rate of syndrome diagnosis in primary care patients who screened positive for dementia, the distribution of differential diagnoses, and factors associated with undiagnosed dementia. METHODS DelpHi-MV (Dementia: life- and person-centered help in Mecklenburg-Western Pomerania) is an ongoing general practitioner (GP)-based, randomized, controlled intervention trial. A total of 4,064 patients (≥70 years, living at home) recruited from 108 participating GP practices were screened for dementia (DemTect < 9). Of 692 eligible patients (17%), a total of 406 subjects (59%) provided informed consent. Present analyses are based on the data of 243 patients with complete baseline assessment on January 1, 2014 (preliminary data). Formal diagnoses were retrieved from the medical records of the treating GPs. A conditional fixed effect regression analysis was performed to analyze factors associated with undiagnosed dementia. RESULTS A total of 40% of patients who screened positive for dementia had been formally diagnosed with dementia. Unspecified dementia was diagnosed in 53%, vascular dementia in 24%, and Alzheimer's disease in 19% of these patients. Undiagnosed dementia was significantly associated with a higher mean score in the Mini-Mental State Examination (odds ratio, 1.11; p < 0.01, 95% confidence interval 1.04-1.18). CONCLUSIONS The diagnosis rate of dementia in German primary care (40%) is well within the range of the international data (20-50%). The results emphasize the need for action to enhance recognition and differential diagnosis of dementia.