Parkinson’s disease (PD) is a progressive neurodegenerative disorder causing motor and non-motor symptoms that can affect independence, social adjustment and the quality of life (QoL) of both patients and caregivers. Studies designed to find diagnostic and/or progression biomarkers of PD are needed. We describe here the study protocol of COPPADIS-2015 (COhort of Patients with PArkinson’s DIsease in Spain, 2015), an integral PD project based on four aspects/concepts: 1) PD as a global disease (motor and non-motor symptoms); 2) QoL and caregiver issues; 3) Biomarkers; 4) Disease progression. Observational, descriptive, non-interventional, 5-year follow-up, national (Spain), multicenter (45 centers from 15 autonomous communities), evaluation study. Specific goals: (1) detailed study (clinical evaluations, serum biomarkers, genetic studies and neuroimaging) of a population of PD patients from different areas of Spain, (2) comparison with a control group and (3) follow-up for 5 years. COPPADIS-2015 has been specifically designed to assess 17 proposed objectives. Study population: approximately 800 non-dementia PD patients, 600 principal caregivers and 400 control subjects. Study evaluations: (1) baseline includes motor assessment (e.g., Unified Parkinson’s Disease Rating Scale part III), non-motor symptoms (e.g., Non-Motor Symptoms Scale), cognition (e.g., Parkinson’s Disease Cognitive Rating Scale), mood and neuropsychiatric symptoms (e.g., Neuropsychiatric Inventory), disability, QoL (e.g., 39-item Parkinson’s disease Quality of Life Questionnaire Summary-Index) and caregiver status (e.g., Zarit Caregiver Burden Inventory); (2) follow-up includes annual (patients) or biannual (caregivers and controls) evaluations. Serum biomarkers (S-100b protein, TNF-α, IL-1, IL-2, IL-6, vitamin B12, methylmalonic acid, homocysteine, uric acid, C-reactive protein, ferritin, iron) and brain MRI (volumetry, tractography and MTAi [Medial Temporal Atrophy Index]), at baseline and at the end of follow-up, and genetic studies (DNA and RNA) at baseline will be performed in a subgroup of subjects (300 PD patients and 100 control subjects). Study periods: (1) recruitment period, from November, 2015 to February, 2017 (basal assessment); (2) follow-up period, 5 years; (3) closing date of clinical follow-up, May, 2022. Funding: Public/Private. COPPADIS-2015 is a challenging initiative. This project will provide important information on the natural history of PD and the value of various biomarkers.

To analyze the main determinants of burden and stress in caregivers of Spanish Parkinson's disease (PD) patients. One-hundred and twenty-one non-demented patients with PD (57.9% males; 70.9 ± 8.2 years old) were included in this cross-sectional, monocenter, evaluation study. Caregivers (n = 121; 71.9% females; 60.2 ± 15 years old) were assessed using the Zarit Caregiver Burden Inventory (ZCBI) and Caregiver Strain Index (CSI). Multiple linear regression methods were used to evaluate factors contributing to caregivers' stress and burden: (i) PD motor dysfunction (ON-state Hoehn & Yahr/Unified Parkinson's Disease Rating Scale [UPDRS] part III and motor complications [UPDRS part IV]); (ii) Mood (Beck Depression Inventory [BDI]); (iii) Non-motor symptoms (Non-Motor Symptoms Scale [NMSS]); (iv) Disability (Schwab & England Activities of Daily Living Scale [ADLS]); and (v) Socio-demographic and other disease-related variables. Zarit Caregiver Burden Inventory and CSI mean scores were 16 ± 13.9 and 2.1 ± 2.3, respectively. High correlation was found between ZCBI and CSI (r = 0.819; P < 0.0001). Moderate to severe burden (ZCBI > 40) was present in 9.1% of caregivers; 5.8% had high levels of stress (CSI ≥ 7). Moderate to strong correlations were observed between patient-related variables (Hoehn&Yahr, UPDRS-III, UPDRS-IV, BDI, NMSS, and ADLS) and ZCBI and CSI (P < 0.0001). Linear regression methods showed that ADLS had the strongest influence on ZCBI and CSI, followed by BDI on ZCBI. Disability (ADLS) and mood (BDI) of patients with PD are the main factors contributing to burden and stress in caregivers.