A new study on the effectiveness of the Apple Watch and iPhone as tools for measuring functional capacity in patients with cardiovascular disease (CVD) has been published by researchers at Stanford University.

The study, which involved 110 participants, found that the health-monitoring capabilities in these products could supplement or replace in-clinic tests for “frailty” in patients with CVD.

Frailty in this case is measured in terms of the distance a patient can travel in a six-minute walk. This is normally tested with a six-minute walk test (6MWT), and frailty was defined in the study “as walking <300m on an in-clinic 6MWT.”