- Garcia DelaRubia S, Pajarone-Fernandez MJ, Sanchez-Solis M, et al
Because exercise is one of the most common triggering factors for asthma in children, the purpose of this study was to determine if there are any differences in postexercise spirometry after treadmill and free running provocation tests.
The results of a treadmill test performed by 30 children with asthma and 30 children without asthma were compared with those of a free running test in similar environmental conditions of temperature, humidity, and exercise intensity, assessed by heart rate as well as airway status at the time of the test.
Seventy-three percent of the patients had a positive treadmill test and 63% had a positive running test. For the spirometric parameters that were used, there were no significant differences in the percent decrease post-exercise after either of the provocation tests. For the forced expiratory volume in 1 second (FEV1), which is the most highly regarded and sensitive diagnostic parameter, the sensitivity was 53% for the treadmill test and 67% for the free-running test and the specificity was 100% for both tests. Peak flow sensitivity was 43% for treadmill and only 27% for free-running with a specificity of 94% and 97%, respectively.
Maintaining the same environmental conditions and exercise intensity, the treadmill and free-running tests can be used interchangeably for the evaluation of exercise-induced asthma.
This is a useful study that demonstrates that treadmill and free-running tests are overall equivalent in the assessment of exercise-induced asthma. This study supports the usefulness of a free-running test for screening purposes, as it appears to be as sensitive as a treadmill, provided spirometry is used as the index, and environmental conditions and exercise intensity are controlled. A free-running test offers the further advantages of familiarity, simplicity of use, and inexpensive status, although it is more difficult to control for cardiopulmonary measurements.