Medication burden and high-risk drug exposure associated with fall-related complications in adults aged 85 years and older presenting to the emergency department: a retrospective observational study

Falls are the leading cause of trauma-related morbidity and mortality in older adults. Although the risk of falls increases sharply after age 80, data on the spectrum of acute complications in the oldest-old (≥ 85 years) remains limited, particularly regarding the contribution of fall-risk-increasing drugs (FRIDs). This study aimed to characterize the prevalence of acute complications and clinical outcomes after falls in patients aged ≥ 85 years attending a private tertiary-care emergency department (ED) in Mexico City, and to examine associations between specific medication classes and individual complications using both univariable and multivariable approaches. Retrospective, cross-sectional, observational study at Hospital Médica Sur (January 2023–March 2025), conducted and reported in accordance with the STROBE statement for observational studies [1]. Patients aged ≥ 85 years presenting to the ED with a primary diagnosis of fall or fall-related trauma were included. Demographic variables, Charlson Comorbidity Index (CCI), number and class of medications, Anticholinergic Cognitive Burden (ACB) score, acute complications, and disposition outcomes were extracted from electronic medical records. Chi-squared tests evaluated unadjusted associations between FRIDs and specific complications; significant associations were subsequently tested in multivariable logistic regression models adjusted for age, sex, CCI category, and ACB score, with effect sizes reported as adjusted odds ratios (aOR) and 95% confidence intervals (CI). A Benjamini-Hochberg false discovery rate (FDR) correction was applied to account for multiple comparisons. Multivariable models were additionally fitted for the clinically important outcomes of in-hospital mortality, hospitalization, and surgical intervention. Data from 228 patients were analyzed (mean age 89.6 ± 3.9 years; 71.1% female). Polypharmacy was present in 36.4% and excessive polypharmacy in 15.4%; and 79.8% used at least one FRID. At least one acute complication was documented in 61.0% of patients. The most frequent complications were contusion (94.7%), traumatic brain injury (57.9%; defined as any physician-documented intracranial or scalp injury identified clinically and/or via protocol-driven CT imaging), any fracture (51.8%), and hip fracture (18.9%). Benzodiazepine use was significantly associated with hip fracture (35.5% vs. 16.2%; p = 0.011; adjusted OR (aOR) 2.93, 95% CI 1.22–7.08), beta-blocker use with traumatic brain injury (72.9% vs. 53.9%; p = 0.018; aOR 2.52, 95% CI 1.22–5.22), diuretic use with lacerations requiring suture (42.9% vs. 19.7%; p = 0.003; aOR 3.23, 95% CI 1.49–7.02), and opioid use with hematoma (29.4% vs. 7.6%; p = 0.003; aOR 3.63, 95% CI 0.98–13.43, attenuated to borderline significance after adjustment). All four associations remained significant after FDR correction (q = 0.012–0.036). In multivariable models of clinical outcomes, hospitalization was independently associated with any fracture (aOR 11.16, 95% CI 5.38–23.13) and higher ACB score (aOR 1.60, 95% CI 1.23–2.08); the mortality model was underpowered (7 events) and yielded no independent predictors. In-hospital mortality was 3.1%. Acute complications after a fall are highly prevalent among the oldest-old presenting to the ED. While polypharmacy was not, several specific FRID classes were significantly associated with individual complications in both unadjusted and confounder-adjusted analyses, supporting the integration of targeted pharmacological deprescribing strategies particularly benzodiazepine review in falls prevention programs for patients aged ≥ 85 years. Given the retrospective design and the absence of frailty and anticoagulant/antiplatelet data, these associations should be regarded as hypothesis-generating and require confirmation in prospective, frailty-adjusted cohorts. 2025-EXT-975.