Sociodemographic determinants of Alzheimer’s disease in primary care: evidence from the province of Salamanca (Spain)

Abstract

Abstract Background Alzheimer’s disease (AD) is the most prevalent form of dementia worldwide, representing a growing public health concern as populations age. While biological mechanisms have been extensively studied, less is known about how sociodemographic determinants - such as residence, education, and socioeconomic context - affect the onset and distribution of AD in Spain. This study explores the association between sociodemographic factors and AD diagnosis among patients in primary health care centers in the province of Salamanca. Methods A cross-sectional, observational, and retrospective study was conducted using data from the Medora 4 electronic health records system of the Castilla y León Regional Health Service (SACYL). A total of 760 patients with a confirmed diagnosis of AD between 2009 and 2019 were randomly selected from an initial cohort of 1,623 individuals (95% confidence level, 2.59% margin of error). Variables analyzed included age, sex, place of residence (urban/rural), educational level, occupation, depressive symptoms, and family history of dementia. Data were analyzed with descriptive and inferential statistics using chi-square and Kruskal–Wallis tests (p < 0.05). Results Conclusion Among the 760 participants, 70% were women (n = 535) and 30% men (n = 225), with a mean age above 65 years. AD prevalence was significantly higher among urban residents (50.8%) than rural residents (49.2%) (p = 0.016). Women were disproportionately affected in both environments, especially in rural areas (74.1% vs. 66.1% in urban areas). Depression was recorded in 40.3% of patients, more frequently among women, though no significant association was observed with AD onset. Advanced age and female sex were confirmed as predominant risk factors. This study reveals a significant urban – rural disparity in AD prevalence in Salamanca, Spain, and confirms the higher vulnerability of older women. The findings underscore the need for targeted prevention and early detection strategies within primary care, particularly in urban settings where prevalence is higher. Understanding these sociodemographic determinants is crucial for designing equitable, community-based dementia care policies.