Journal of Rehabilitation Medicine 51-8 | Page 51

J Rehabil Med 2019; 51: 587–597 ORIGINAL REPORT VALIDITY, INTERNAL CONSISTENCY AND SELF-RATED CHANGE OF THE PATIENT ENABLEMENT INSTRUMENT IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN Paul ENTHOVEN, PhD 1 , Anneli PEOLSSON, PhD 1 , Maria LANDÉN LUDVIGSSON, PhD 1,2 , Johanna WIBAULT, PhD 1,3 , Gunnel PETERSON, PhD 1,4 and Birgitta ÖBERG, PhD 1 From the 1 Department of Medical and Health Sciences, Division of Physiotherapy, Linköping University, Linköping, 2 Department of Rehabilitation and Department of Medical and Health Sciences, Linköping University, Motala, 3 Department of Activity and Health, and Department of Medical and Health Sciences, Linköping University, Linköping, and 4 Centre for Clinical Research Sörmland, Uppsala University, Eskilstuna, Sweden Objective: Patient enablement reflects patient’s un- derstanding of and coping with illness. The aim of this study was to investigate the content validity, construct validity, internal consistency and self- rated change (SRC) of the Patient Enablement In- strument (PEI) in patients with whiplash-associated disorders, cervical radiculopathy and mixed chronic pain treated in different settings. Design: Psychometric analyses. Participants: Patients with disabling non-malignant chronic musculoskeletal pain. Methods: Participants answered questionnaires on disability (Neck Disability Index (NDI) or Functional Rating Index (FRI)), anxiety/depression (Hospital Anxiety and Depression Scale; HADS) and general health (EuroQol; EQ-5D). Content validity, construct validity (confirmatory factor analysis), internal con- sistency and cut-off for SRC were investigated for the PEI after treatment. The SRC value was the re- ceiver operating characteristic (ROC) curve optimal cut-off point. Results: After treatment all items were completed by 516 patients (mean standard deviation (SD) age 45.1 years (SD 10.1), women 75% (n  = 385)). The 1-factor PEI model had approximate fit to the data. The internal consistency Cronbach’s alpha was bet- ween 0.878 and 0.929 for the 3 groups. Correlations between the PEI and the NDI/FRI, HADS and EQ-5D were fair to good. The SRCROC for whiplash-asso- ciated disorders, cervical radiculopathy and mixed chronic pain groups was 5, 6 and 4 points in the PEI, respectively. Conclusion: The PEI showed fair content validity, construct validity and internal consistency. How­ ever, the scale needs further development to impro- ve measurement of change. Key words: validity; reliability; primary care; whiplash inju- ry; neck pain; chronic pain; outcome assessment. Accepted May 29, 2019; Epub ahead of print Jun 14, 2019 J Rehabil Med 2019; 51: 587–597 Correspondence address: Paul Enthoven, Department of Medical and Health Sciences, Campus US, Entrance 78, Floor 15, SE-581 83 Linköping, Sweden. E-mail: [email protected] LAY ABSTRACT Patient enablement reflects patients understanding of and coping with illness. This study investigated mea- surement properties and minimal important change in the Patient Enablement Instrument (PEI) in patients with whiplash-associated disorders, cervical radiculo- pathy and mixed chronic pain treated in different care settings. After treatment, all items were completed by 516 patients (mean age 45.1 years (standard deviation 10.1), women 75% (n  = 385)). Fair measurement pro- perties were found for the PEI for the included groups of patients, indicating that the PEI is suitable for use in patients with chronic musculoskeletal pain. The minimal important change in the PEI for whiplash-associated di- sorders, cervical radiculopathy and mixed chronic pain groups was 5, 6 and 4 points, respectively, indicating that a study-specific minimal important change should be applied. However, the cale needs further develop- ment to improve measurement of changes. P atient enablement reflects the extent to which a patient can understand and cope with his or her illness (1, 2). The Patient Enablement Instrument (PEI) is a validated consultation outcome measure that was developed for use in primary care (3, 4). The instru- ment was subsequently used in a number of studies with different populations and settings (5–9), with some studies reporting its validity (3–6, 10, 11) and reliability (1, 3, 6, 10). Outcomes after different treatment/rehabilitation efforts, especially in chronic pain, sometimes fail to affect traditional outcomes, such as pain and disabi- lity. It is important to empower patients and to have strategies to cooperate with and support patients in order to help them regain power over their own lives, accept their current status and future outlook, and help them achieve better health and reach their personal goals (12). Measuring patient enablement might be a valuable complement to a biopsychosocial approach in order to understand the goals of broad interventions for patients with chronic pain. In previously published studies we showed that patients who received specific This is an open access article under the CC BY-NC license. www.medicaljournals.se/jrm Journal Compilation © 2019 Foundation of Rehabilitation Information. ISSN 1650-1977 doi: 10.2340/16501977-2573