[jdmcnugent]

Speaking from an orthopedic perspective (though most fields are similar), there are literally thousands of ways to measure this, they are called (not surprisingly) outcome measures and they are basically the foundation of almost every medical study. Many are a collection of questions or items that add up to a given score which is how they are able to be statistically analyzed.

Some are subjective like pain (VAS or visual analog pain scale, “rate your pain 1-10”), ability to do daily activities, “would you have this procedure again?”, return to pre-injury activity level, etc.

Others are objective like range of motion, strength, bone healing noted on Xray or ct, tendon / ligament healing observed on mri, histiologic healing observed from follow up biopsy, rehospitilzation rates, revision surgery rates, infection rates, or mortality rates (the ultimate objective outcome measure).

There is hardly a shortage of outcome measures out there, and researchers propose new ones all the time, but they need to be validated as relevant and accurate by other studies before they are widely adopted.

http://www.orthopaedicscores.com