Cohort Profile: A Descriptive Analysis of Patients Aged 75 Years and Older with Public Health Coverage in Madrid at Baseline, Including a 5-Year Preobservational Period (2015–2019)

Background/Objectives: Population aging increases the healthcare burden of chronic diseases. We aimed to characterize the sociodemographic and clinical characteristics of Aged Madrid, a cohort comprising 98.6% of the population aged 75 years and older in Madrid, Spain. Methods: Observational study with a five-year retrospective baseline period (2015–2019) to assess baseline vascular and metabolic risk. Data were taken from primary care electronic medical records, hospital discharge summaries, and pharmacy records. Results: 587,603 individuals (mean age: 84 years ± 5.8 years, 61.3% women) were analysed. Obesity affected 31.3% (more frequent in women), while type 2 diabetes occurred in 23.8% (predominantly in men). Hypertension (52.8%), dyslipidaemia (61.6%), and chronic kidney disease (21.7%) were more frequent in women. Atrial fibrillation was the leading cardiovascular condition in women (15.1%), while acute myocardial infarction predominated in men (8.2%). The most prescribed drug classes were antihypertensives (53.8%), statins (44.2%), and oral antidiabetics (26.4%). Among antihypertensives, diuretics (53.9%), ACE inhibitors (27.4%), and ARBs (25.3%) were most used, often in combinations such as diuretics + ACE inhibitors (30.1%). Diabetes treatments favoured metformin and DPP-4 inhibitors; 5.2% received insulin. Conclusions: Sex-based differences emerged in biochemical, anthropometric, and lifestyle variables. Men showed a higher prevalence of cardiovascular diseases and several cardiometabolic risk factors, while women used fewer lipid-lowering and antidiabetic agents. Diuretics were the predominant antihypertensives, and antidiabetic therapy largely followed guideline recommendations. Although 60% of statin users had no prior cardiovascular disease, and their use was concentrated mainly among individuals with major cardiometabolic risk conditions and declined with advancing age, suggesting an age- and risk-sensitive prescribing pattern rather than indiscriminate use.