Dynamic weight-bearing assessment of pain in knee osteoarthritis: construct validity, responsiveness, and interpretability in a research setting

TY - JOUR

T1 - Dynamic weight-bearing assessment of pain in knee osteoarthritis

T2 - construct validity, responsiveness, and interpretability in a research setting

AU - Klokker, Louise

AU - Christensen, Robin

AU - Wæhrens, Eva E

AU - Bandak, Elisabeth

AU - Bartholdy, Cecilie

AU - Bliddal, Henning

AU - Henriksen, Marius

PY - 2016/6/16

Y1 - 2016/6/16

N2 - Background: The Osteoarthritis Research Society International (OARSI) has suggested to asses pain after specific activities consistently in clinical trials on knee OA. The Dynamic weight-bearing Assessment of Pain (DAP) assesses pain during activity (30 s of performing repeated deep knee-bends from a standing position). The purpose of this study is to evaluate the construct validity, responsiveness, and interpretability of the DAP for knee osteoarthritis (OA). Methods: One-hundred participants with knee OA were tested twice each with the DAP, the Knee injury and Osteoarthritis Outcome Score (KOOS), six-minute-walk-test (6MWT), and 6-min-walk-test with subsequent pain rating (6MWTpain), and once with a transition questionnaire (TRANS-Q) for the patient-reported change in pain after 12 weeks of exercise. Construct validity (baseline-scores) and responsiveness (change-scores) were estimated by Spearman Correlation Coefficients. We hypothesized that no correlations would be excellent (<0.7) (divergent validity), except for the 6MWTpain (convergent validity). The TRANS-Q was used for interpreting the DAP change-scores in terms of responsiveness and Minimal Important Change (MIC). Results: Divergent validity with the KOOS subscales (r = -0.31 to-0.45) and the 6MWT (r = -0.25) was supported. Convergent validity with the 6MWTpain was not supported (r = 0.54). The DAP change-scores corresponded to patient-reported change in pain (TRANS-Q), while correlations with change-scores on the other instruments were <0.35. The MIC was 2.4 DAP points. Conclusions: The DAP possesses divergent validity compared to other instruments for knee OA, supporting the potential for this new way of assessing pain directly during activity. Importantly, the DAP change-scores correspond to patient-reported changes in pain, showing responsiveness. A change of 2.4 or more can be interpreted as clinically relevant. The DAP is a promising alternative to using 'pain on walking' as a clinical trial inclusion criterion/outcome.

AB - Background: The Osteoarthritis Research Society International (OARSI) has suggested to asses pain after specific activities consistently in clinical trials on knee OA. The Dynamic weight-bearing Assessment of Pain (DAP) assesses pain during activity (30 s of performing repeated deep knee-bends from a standing position). The purpose of this study is to evaluate the construct validity, responsiveness, and interpretability of the DAP for knee osteoarthritis (OA). Methods: One-hundred participants with knee OA were tested twice each with the DAP, the Knee injury and Osteoarthritis Outcome Score (KOOS), six-minute-walk-test (6MWT), and 6-min-walk-test with subsequent pain rating (6MWTpain), and once with a transition questionnaire (TRANS-Q) for the patient-reported change in pain after 12 weeks of exercise. Construct validity (baseline-scores) and responsiveness (change-scores) were estimated by Spearman Correlation Coefficients. We hypothesized that no correlations would be excellent (<0.7) (divergent validity), except for the 6MWTpain (convergent validity). The TRANS-Q was used for interpreting the DAP change-scores in terms of responsiveness and Minimal Important Change (MIC). Results: Divergent validity with the KOOS subscales (r = -0.31 to-0.45) and the 6MWT (r = -0.25) was supported. Convergent validity with the 6MWTpain was not supported (r = 0.54). The DAP change-scores corresponded to patient-reported change in pain (TRANS-Q), while correlations with change-scores on the other instruments were <0.35. The MIC was 2.4 DAP points. Conclusions: The DAP possesses divergent validity compared to other instruments for knee OA, supporting the potential for this new way of assessing pain directly during activity. Importantly, the DAP change-scores correspond to patient-reported changes in pain, showing responsiveness. A change of 2.4 or more can be interpreted as clinically relevant. The DAP is a promising alternative to using 'pain on walking' as a clinical trial inclusion criterion/outcome.

KW - Adult

KW - Aged

KW - Exercise Test

KW - Female

KW - Humans

KW - Male

KW - Middle Aged

KW - Osteoarthritis, Knee

KW - Pain

KW - Pain Measurement

KW - Quality of Life

KW - Reproducibility of Results

KW - Sensitivity and Specificity

KW - Surveys and Questionnaires

KW - Walking

KW - Weight-Bearing

KW - Journal Article

KW - Randomized Controlled Trial

KW - Research Support, Non-U.S. Gov't

U2 - 10.1186/s12955-016-0495-6

DO - 10.1186/s12955-016-0495-6

M3 - Journal article

C2 - 27306539

SN - 1477-7525

VL - 14

JO - Health and Quality of Life Outcomes

JF - Health and Quality of Life Outcomes

M1 - 91

ER -