Rationale:
The six-minute walk (6MW) test has been used for many years in North Carolina pulmonary rehabilitation (PR) facilities to periodically assess changes in functional performance following both short- and long-term PR participation. Currently, little is known about how 6MW performance changes over time in long-term PR participants of medically supervised programs.
Objective:
This investigation was designed to assess differences in 6MW performance following up to 24 months (m) of participation in men and women of North Carolina PR programs.
Methods:
Subjects aged 20 to 89 years from 22 multidisciplinary PR programs performed 6MW tests following standardized instructions at PR entry and immediately following 3, 6, 12, 18 and 24 m of PR participation. Six-minute walk distance (feet) was compared across time intervals with repeated measures analysis of variance.
Results:
In those who participated for 3 m (N = 1337), 6MW distance increased (mean +/- standard deviation) from PR entry to 3 m (1048 +/- 361 to 1261 +/- 360, P < 0.0001). In those who participated for 6 m (N = 287), 6MW distance increased from PR entry to 3 m (1145 +/- 340 to 1314 +/- 335, P < 0.0001) and again from 3 m to 6 m (1314 +/- 335 to 1345 +/- 386, P < 0.05). In those who participated for 12 m (N = 137), 6MW distance increased from PR entry to 3 m (1199 +/- 329 to 1421 +/- 386, P < 0.0001), but not from 3 m to 6 m (1376 +/- 318 to 1420 +/- 356, P = 0.097), 6 m to 12 m (1420 +/- 356 to 1421 +/- 386, P = 1.0), or 3 m to 12 m (1376 +/- 318 to 1421 +/- 386, P = 0.17). In those who participated for 18 m (N = 73), statistically significant improvements in 6MW performance were seen from PR entry to each follow-up period (P < 0.0001), but not from 3 m or 6 m to each follow-up period (P > 0.05). The same relationships held true for those who participated in PR for 24 months (N = 46).
Conclusions:
Six-minute walk performance improves in men and women following 3 m of PR participation and then again after 6 m in the long-term participants. Scores do not improve from 6 m to 12 m, 18 m, or 24 m in the long-term participants, but remain significantly higher than PR entry values. Participation in medically supervised PR is recommended for up to 2 years for maintenance of the improvements observed in physical work performance (as measured by the 6MW test) after 3 m and 6 m of PR participation.