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

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 unclear. 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. 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. 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 dementia 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). 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 associated with a higher incidence rate ratio for dementia than total intravenous anaesthesia (TIVA).