The strongest indication for the 6MWT is for measuring the response
to medical interventions in patients with moderate to
severe heart or lung disease. The 6MWT has also been used as
a one-time measure of functional status of patients, as well as a
predictor of morbidity and mortality (see Table 1 for a list of
these indications). The fact that investigators have used the
6MWT in these settings does not prove that the test is clinically
useful (or the best test) for determining functional capacity or
changes in functional capacity due to an intervention in patients
with these diseases. Further studies are necessary to determine
the utility of the 6MWT in various clinical situations.