Figure 1From: Measurement of acute nonspecific low back pain perception in primary care physical therapy: reliability and validity of the brief illness perception questionnaire Bland Altman plot for the test-retest reliability of the IPQ-B. A total of 84 patients participated in the test-retest assessment. The dotted line represents no difference between test and retest. The central line representing the mean difference between test and retest scores, which was - 4.1, and the 95% limits of agreement are presented as flanking lines.Back to article page