See the text below the calculator for more information on the frailty index.
The Frailty Index (FI) is defined as the proportion of deficits present in an individual out of the total number of age-related health variables considered.
Clinicians can opt to consider health deficits that are routinely collected in health assessments, such as some chronic diseases, signs, symptoms, laboratory abnormalities, cognitive impairments, and disabilities in activities of daily living.
Frailty Index (FI) = No. of health deficits present / No. of health deficits measured
For example, an elderly patient with 20 health deficits out of 50 considered has a FI score of 0.4 whilst another elderly patient with 10 health deficits out of 50 considered, has a FI of 0.2.
Send Us Your Feedback
Steps on how to print your input & results:
1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.
2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.
Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.
About the Frailty Index
The FI (developed by Rockwood, Mitnitski et al) can be used in research and health settings as a measure of health status of older individuals as:
- Proxy measure of aging;
- Predictor of risk/vulnerability to poor outcomes.
The Frailty Index is defined as the proportion of deficits present in an individual out of the total number of age-related health variables considered.
FI Score = Number of health deficits present / Number of health deficits measured
For example, an elderly patient with 20 health deficits out of 50 considered has a FI of 0.4 whilst another elderly patient with 10 health deficits out of 50 considered, has a FI of 0.2.
A Frailty Index can be created by utilizing health deficits that are routinely collected in health assessments, such as chronic diseases, symptoms and signs, laboratory, imaging and echocardiographic abnormalities, example of cognitive impairments or disabilities in ADLs (activities of daily living).
There is a standard procedure for creating a frailty index (please study linked in the references below) that starts from solving the need to operationalize frailty (defined as increased vulnerability to adverse outcomes).
Across several frailty index measures and studies, people were found to accumulate deficits, on average, at about 0.03/year and the frailer the person was (the higher the deficit count) the more vulnerable they were found to adverse outcomes.
Estimates were found to be more stable and with sufficient accuracy for predicting adverse outcomes when at least 30-40 health deficits were considered.
The FI shows a consistent, sub-maximal limit at about 2/3 of the deficits that are considered. For example, if a frailty index is composed of 30 items, the most that anyone will have wrong with them is not 30, but 20.
Variables can be included in a frailty index if they satisfy the following 5 criteria:
- Deficits must be associated with health status (for example, not be just age related);
- A deficit's prevalence must generally increase with age (although there may be exceptions);
- The chosen deficits must not saturate too early (for example presbyopia and age-related lens changes occur nearly universally by age 55 so saturate too early);
- Chosen deficits must cover a range of systems (for example, not just cognitive impairment items);
- Deficits must be the same from one iteration to the other of the index, if used serially on the same people.
Searle SD, Mitnitski A, Gahbauer EA, Gill TM, Rockwood K. A standard procedure for creating a frailty index. (2008) BMC Geriatrics. 8 (1): 24.
Peña FG, Theou O, Wallace L, Brothers TD, Gill TM, Gahbauer EA, Kirkland S, Mitnitski A, Rockwood K. Comparison of alternate scoring of variables on the performance of the frailty index. BMC Geriatr. 2014; 14: 25.
No. Of Variables: 2
Year Of Study: 2014
Published On: April 28, 2020 · 12:00 AM
Last Checked: April 28, 2020
Next Review: April 28, 2025