indicates the significance of the F ratio in this
study or p
There are different types of ANOVA,
but the focus of these analysis techniques is on examining differences between
two or more groups. The simplest is the one-way ANOVA, but many of the studies
in the literature include more complex ANOVA techniques. A commonly used ANOVA
technique is the repeated-measures analysis of variance, which is used
to analyze data from studies where the same variable(s) is (are) repeatedly
measured over time on a group or groups of subjects. The intent is to determine
the change that occurs over time in the dependent variable(s) with exposure to
the independent treatment variable(s).
Source: Baird, C. L., & Sands, L. (2004). A pilot study of
the effectiveness of guided imagery with progressive muscle relaxation to
reduce chronic pain and mobility difficulties of osteoarthritis. Pain
Management Nursing, 5 (3), 97–104.
“Osteoarthritis (OA) is a common,
chronic condition that affects most older adults. Adults with OA must deal with
pain that leads to limited mobility and may lead to disability and difficulty
maintaining independence” (Baird & Sands, 2004, p. 97). Baird and Sands
(2004) conducted a longitudinal, randomized clinical trial pilot study “to
determine whether Guided Imagery (GI) with Progressive Muscle Relaxation (PMR)
would reduce pain and mobility difficulties of women with OA” (Baird &
Sands, 2004, p. 97). The sample included 28 women over 65: 18 women were
randomly assigned to the intervention group, and 10 were randomly assigned to
the control group. “The treatment consisted of listening twice a day to a
10-to-15 minute audiotaped script that guided the women in GI with PMR.
Repeated measures ANOVA revealed a significant difference between the two
groups in the amount of change in pain and mobility difficulties they
experienced over 12 weeks. The treatment group reported a significant reduction
in pain and mobility difficulties at week 12 compared to the control group.
Members of the control group reported no differences in pain and nonsignificant
increases in mobility difficulties. The results of this pilot study justify
further investigation of the effectiveness of GI with PMR as a self-management
intervention to reduce pain and mobility difficulties associated with OA”
(Baird & Sands, 2004, p. 97).
Relevant Study Results
“Repeated-measures ANOVA revealed a
significant difference between the two groups in how much change in pain they
experienced for 12 weeks (F[1, 26] = 4.406, p =
0.046). The 17 participants in the intervention group reported a significant
reduction in pain (p Figure 1)” (Baird & Sands, 2004, p. 100).
FIGURE 1 Change in pain over 12 weeks. Pain was significantly less in
the guided imagery intervention group (p = .046).
Baird, C. L., & Sands, L. (2004).