OBJECTIVES: There is a lack of long-term data from the real-life setting to document the clinical evolution of Alzheimer’s disease (AD) patients, especially in moderate AD where disease management becomes more complex. The EVOCOST study aims to describe how moderate AD is associated with a relevant disease-related disability progression and an increase in caregiver burden. METHODS: The EVOCOST study is a prospective 12-month multicentre cohort study recruiting community-dwelling moderate AD patients in Spain. Visits were scheduled at baseline, 6 and 12 months according to routine clinical practice. Data on socio-demographic characteristics, disease history and comorbidities were collected at baseline. Clinical evolution and caregiver burden were measured using the following assessment tools: Global Deterioration Scale (GDS) for severity, Mini-Mental State Examination (MMSE) for cognition, Clinical Global Impression (CGI) for global status, Basic and Instrumental Activities of Daily Living (BADL and IADL) for functional disability, brief Neuropsychiatric Inventory (NPI-Q) for behaviour, Zarit Burden Interview (ZBI) and time spent on care for caregiver burden. Changes from baseline were calculated and tested with Wilcoxon signed rank tests. RESULTS: A total of 209 patients were included at baseline, 76.1% of them were women, with a mean age of 78.4 years and a mean MMSE of 15.2. At the 12-month visit, data were available on 174 patients (patient’s attrition rate 16.8%). Clinical symptoms worsened significantly during the 12-month study follow-up in terms of severity (DGDS=+0.5, p<0.001), cognition (DMMSE=-2.9, p<0.001), global status (DCGI=+0.3, p<0.001), and function (DBADL=-1.7, p<0.001; DIADL=-1.2, p<0.001). No significant change was observed on behaviour (DNPI severity=+0.5, p=0.325; DNPI distress=+0.4, p=0.375). Caregiver burden also worsened significantly (DZBI=+2.5, p=0.002; Dtime spent on care=+56hours per month, p<0.001). CONCLUSIONS: The EVOCOST study illustrates well the patient clinical worsening and the increase in caregiver’s burden associated with management of moderate AD.