FUSE - Feasibility of Patient Held Sensors for Medical Emergencies

Rationale: Abnormalities of vital signs are quantified by comparison with 'usual' ranges, which are those observed in resting healthy populations. It might be more appropriate to compare vital sign values of an individual that is in distress with their own usual values recorded when they were stable and well. Wearable sensors might make this possible at scale. Objectives: * To quantify the difference between heart rate on admission to acute care compared to the previously recorded vital signs when 24 hours and 1 week prior of the same patient. * The change in daily steps taken by the patient in the week prior to admission to acute care * To assess the feasibility of using heart rate data from patients' own wearable sensors. Study design: An asynchronous, international, multicentre observational study using the Flash Mob Research design. Study population: Patients aged 18 years and up who present at the Emergency Department, Acute Medical Department or Ambulatory Emergency Care with an acute complaint. Main study parameters/endpoints: * The difference between heart rate measured on presentation to acute care services, and measured prior when stable and well. * The daily number of steps taken in the week prior to presentation to acute care services. * The proportion of patients assessed for an acute complaint who have recordings of vital signs measured before they became unwell. * A description of the population that uses devices that collect vital signs in terms of sex, age-group, digital literacy, and their severity of illness on presentation (as measured by a standard set of vital signs and frailty). * The devices used to measure vital signs before they became unwell, and the vital signs they measure. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: There is no burden or risk associated with participation to patients, and no immediate benefit.