Dementia risk amongst older adults with hip fracture receiving general anaesthesia or regional anaesthesia: a propensity-score-matched population-based cohort study

Background: Preclinical studies have indicated that anaesthesia is an independent risk factor for dementia, but the clinical associations between dementia and different types of general anaesthesia or regional anaesthesia remain un-clear. We conducted a population-based cohort study using propensity-score matching to compare dementia incidence in patients included in the Taiwanese National Health Insurance Research Database who received various anaesthetic types for hip fracture surgery.Methods: Patients aged >= 65 yr who received elective hip fracture surgery from 2002 to 2019 were divided into three groups receiving either inhalational anaesthesia (GA), total intravenous anaesthesia -general anaesthesia (TIVA-GA), or regional anaesthesia (RA), and matched in a 1:1 ratio. The incidence rates of dementia were then determined.Results: Propensity-score matching yielded 89 338 patients in each group (N=268 014). Dementia incidence rates in the inhalational GA, TIVA-GA, and RA groups were 4821, 3400, and 2692 per 100 000 person-years, respectively. The de-mentia incidence rate ratio (95% confidence interval [CI]) for inhalational GA to TIVA-GA was 1.19 (1.14-1.25), for inhalational GA to RA was 1.51 (1.15-1.66), and for TIVA-GA to RA was 1.28 (1.09-1.51).Conclusions: The incidence rate ratios of dementia amongst older adults undergoing hip fracture surgery were higher for those receiving general anaesthesia than for those receiving regional anaesthesia, with inhalational anaesthesia asso-ciated with a higher incidence rate ratio for dementia than total intravenous anaesthesia (TIVA).