Responsiveness and clinically important differences of the PROMIS short form-depression 8a, anxiety 8a, and PASS-20 in individuals with chronic low back pain.

Abstract

Depression and anxiety are the most commonly reported mental health conditions. The Patient-Reported Outcomes Measurement Information System Short Form v1.0-Depression 8a (PROMIS-D-8a), Anxiety 8a (PROMIS-Anx8a), and Pain Anxiety Symptoms Scale-20 (PASS-20) measures were designed to assess depression, general anxiety, and pain-related anxiety, respectively. To examine the responsiveness and estimate the clinically important differences (CIDs) of the Thai version of these measures in individuals with chronic low back pain (CLBP). The study sample comprised 144 participants with CLBP. Responsiveness was evaluated by calculating the change scores, effect sizes (ESs), standardized response means (SRMs), area under the curve (AUC), and correlations between the change scores and associated Global Perceived Effect (GPE). We also estimated CIDs by the difference in mean change score between improved and unchanged groups and standard error of measurement (SEM) for each measure. Statistically significant differences in the mean change scores, ESs, and SRMs supported the responsiveness of all measures. The AUCs achieved acceptable discriminatory ability (0.71-0.72) for moderate improvement but not for any improvement (0.65-0.68). The correlations between GPE and change scores on all measures were low (r ranging 0.28-0.33). The estimated CIDs for the PROMIS-D-8a, PROMIS-Anx8a, and PASS-20 were 3.64, 4.20, and 8.80, respectively. The PROMIS-D-8a, PROMIS-Anx8a, and PASS-20 measures were sensitive for detecting clinical changes over time in individuals with CLBP. The CID values can be used as reference points for assessing meaningful improvements in the domains assessed by these scales in clinical and research practice.