Background: Anaemia in the elderly is associated with a number of health-related functional declines, such as frailty, disability and muscle weakness. These may contribute to falls which, in the elderly, result in serious injuries in perhaps 10% of cases.
Objective: To investigate whether anaemia increases the risk of injurious falls in an elderly population.
Method: Health insurance claims and laboratory test results data from January 1999 to April 2004 for 47 530 individuals >or=65 years of age enrolled in over 30 managed care plans were analysed. An open-cohort design was employed to classify patients' observation periods by anaemia status (based on the WHO definition) and haemoglobin (Hb) level category. Injurious falls outcomes were defined as an injurious event claim, within 30 days after a fall claim, for fractures of the hip/pelvis/femur, vertebrae/ribs, humerus or lower limbs; Colles' fracture; or head injuries/haematomas. Univariate and multivariate (adjusted for age, gender, health plan, history of falls, co-morbidities and concomitant medications) analyses were conducted. Subset analyses based on injurious falls of the hip and head were also conducted.
Results: In the univariate analysis, anaemia increased the risk of injurious falls by 1.66 times (95% CI 1.41, 1.95) compared with no anaemia. The incidence of injurious falls increased from 6.5 to 15.8 per 1000 person-years when Hb levels decreased from >or=13 to <10 g/dL (trend test: p < 0.001). Multivariate analysis confirmed that Hb levels were significantly associated with the risk of injurious falls (rate ratio = 1.47, 1.39 and 1.14 for Hb levels of <10, 10-11.9 and 12-12.9 g/dL, respectively, compared with Hb >or=13 g/dL; p < 0.001). Even stronger linear negative trends were observed in the subsets of hip and head injurious falls.
Conclusion: Anaemia was significantly and independently associated with a risk increase for injurious falls. Furthermore, the risk of injurious falls increased as the degree of anaemia worsened. Correction of anaemia, a modifiable risk factor, warrants further investigation as a means of preventing falls in the elderly.