Frailty among middle-aged and older Canadians: Population norms for the frailty index using the Canadian Longitudinal Study on Aging

Background: frailty is a public health priority now that the global population is ageing at a rapid rate. A scientifically sound tool to measure frailty and generate population-based reference values is a starting point. Objective: in this report, our objectives were to operationalize frailty as deficit accumulation using a standard frailty index (FI), describe levels of frailty in Canadians ≥45 years old and provide national normative data. Design: this is a secondary analysis of the Canadian Longitudinal Study on Aging (CLSA) baseline data. Setting/participants: about 51,338 individuals (weighted to represent 13,232,651 Canadians), aged 45-85 years, from the tracking and comprehensive cohorts of CLSA. Methods: after screening all available variables in the pooled dataset, 52 items were selected to construct an FI. Descriptive statistics for the FI and normative data derived from quantile regressions were developed. Results: the average age of the participants was 60.3 years (95% confidence interval [CI]: 60.2-60.5), and 51.5% were female (95% CI: 50.8-52.2). The mean FI score was 0.07 (95% CI: 0.07-0.08) with a standard deviation of 0.06. Frailty was higher among females and with increasing age, and scores >0.2 were present in 4.2% of the sample. National normative data were identified for each year of age for males and females. Conclusions: the standardized frailty tool and the population-based normative frailty values can help inform discussions about frailty, setting a new bar in the field. Such information can be used by clinicians, researchers, stakeholders and the general public to understand frailty, especially its relationship with age and sex.