There are many frailty measurement tools used in hospitals and in primary care services. Should we use different frailty measurement tools across the different settings, or should we just use one frailty measurement tool for all settings?
Most important part of it -whether the measurement tool is validated in the setting. Mostly we use different tool for hospital and primary care setting as the scenario and context of measurement varies
The ideal index should be the one that could be used in every scenario. However, such instrument does not exist, especially when talking about frailty.
Several keys should be considered, such as validity, generalizability, stability, repeatability.
It is more important to have a clear objective. If you are aiming to treatment, then use an instrument which is sensitive to change in a short period. If you are aiming to diagnosis, then use an instrument with appropriate sensitivity and specificity. In case you are aiming to measure the economic impact of the diseases, then... ...and so on.
We must keep in mind that a specific objective will have as many advantages as limitations. And everything comes to the researcher choice, considering that limitations should be justified properly.