A proposal for a self-rated frailty index and status for patient-oriented research

Frailty indices are important predictors of major health outcomes, but mostly designed by and for researchers and specialists. Three of the most commonly used theory-based indices are composite measures that are subject to arbitrary assumptions and biases introduced due to data processing. A complicated index can be simplified with fewer items. The theory-based frailty indices are not optimal and neglect patients' perspectives. This study aims to compare different definitions of frailty and propose a self-rated measure of frailty index and status.

Frailty was defined differently by laypeople and researchers/clinicians. Patients' and laypeople's perspectives seemed neglected. Existing frailty indices had shortcomings related to the use of composite measures, assumptions of frailty theories, and the lack of novel information. To avoid these shortcomings, we suggested asking individuals "on a scale of 0 to 10, how frail do you think you are?" and "by answering yes or no, do you consider yourself to be frail?" to determine frailty on continuous and dichotomous scales respectively. However, there will be other issues emerging with these new measures, such as the need for feasibility and validity studies, as well as acceptability by researchers.