Frailty is characterised as a loss of resilience, covering a spectrum of health issues that are collectively associated with a person’s ability to recover from illnesses and injuries. It is broadly used in healthcare settings and routinely measured in UK primary care. However, little is known about frailty in the ambulance setting, or its association with outcomes relevant to ambulance services. We conducted an observational study of ambulance patients in North East England, to assess the feasibility of routinely measuring frailty. I will discuss the challenges we found in training study paramedics to collect frailty data and mitigating biases in the data.