Matheson LN, Mooney V, Holmes D, Leggett S, Grant J, Negri S, Holmes B. A test to measure lift capacity of physically impaired adults: Part II. Reactivity in a patient sample. Spine, 1995;20(19): 2130-2134.
Test reactivity is the based on the idea that experience with a test may affect performance on subsequent tests, independent of what the test purports to measure. The reactivity of a test of lift capacity was studied in a single-blind randomized clinical trial in which subjects were assigned to one of two groups. One group received lift testing before and after a therapeutic trial while the other group received lift testing only at the conclusion of the therapeutic trial.
The objective of this study was to measure the reactivity of a lift capacity test over the course of treatment.
Summary of Background Data
The reactivity of a test is an important criteria by which an outcome measure must be judged. Change in response to treatment is assumed to be independent of changes that are due to the evaluee’s experience with the test, although this is rarely addressed.
The EPIC Lift Capacity Test was administered to 55 low-back pain patients in a treatment program after randomization into a pre-test/post-test and a post-test only group. Additional measures were taken on a pre-test/post-test basis for all subjects.
Analyses of variance demonstrated no difference between the randomized groups after treatment. However, the pre-test/post-test group demonstrated significant improvement over the course of treatment. Other measures of outcome were similarly affected.
The reactivity of the EPIC Lift Capacity test over an eight-week treatment regimen that did not include lifting tasks is negligible.
A standardized lift capacity test was studied in terms of its reactivity and sensitivity to change as the result of treatment. A single-blind randomized clinical trial was used to study the possible effect of prior testing on subsequent test performance. Reactivity was found to be negligible.