https://orcid.org/0000-0002-7613-4801
Abstract
To externally validate the polymyalgia rheumatica (PMR)-impact scale.
Prospective cohort study at the University Hospitals Leuven (Belgium). Recently diagnosed PMR patients were included between July 2022 and December 2023 and followed until 1 year after diagnosis. All patients filled in the PMR-impact scale, HAQ-DI, SF-36 and a visual analogue scale for pain at every visit. Internal consistency, floor- and ceiling effects, construct validity, responsiveness and discriminatory power for detecting relapse of the PMR-impact scale were assessed.
Fifty-five PMR patients (mean age 71 years, 47% female) were included, who had a total of 246 visits. Internal consistency, construct validity and responsiveness met the quality criteria for the symptoms, function and emotional and psychological well-being subdomains. The internal consistency of the glucocorticoid side effects subdomain was insufficient and only one of the three hypotheses for construct validity were met. The function and emotional and psychological well-being subdomains showed a floor effect, while no ceiling effect was observed. The symptoms, function and emotional and psychological well-being subdomains had a good discriminatory power for detecting relapse (AUC 0.89, 0.86 and 0.72, respectively), but the PMR-activity score performed better (AUC 0.94, p < 0.05 for all subdomains).
This study validates the good measurement properties of the symptoms, function and emotional and psychological well-being subdomains of the PMR-impact scale. In contrast, the glucocorticoid side effects subdomain did not show adequate internal consistency and construct validity, necessitating further validation and possibly refinement of its items prior to application in clinical trials or daily practice.
Lay Summary
What does this mean for patients?
Polymyalgia rheumatica (PMR) is an inflammatory disease characterized by pain and morning stiffness in the shoulders, pelvic girdle and neck. The PMR-impact scale is a recently developed questionnaire that allows patients to report how PMR affects their daily life. This study validates the PMR-impact scale in a distinct patient cohort. Researchers followed 55 patients with a recent diagnosis of PMR for one year, evaluating different aspects of the scale, including its reliability, validity, responsiveness and ability to detect disease relapse. The study found that the symptoms, function, and emotional and psychological well-being subdomains of the scale performed well, showing good reliability, validity, and responsiveness. These subdomains also effectively identified PMR relapses. However, the glucocorticoid side effects subdomain did not meet the required quality criteria, suggesting the need for further improvement. Overall, the PMR-impact scale is a useful tool for measuring the impact of PMR on patients’ lives from the patient’s perspective, but refinements are needed, particularly for assessing glucocorticoid side effects, before widespread use in research or clinical practice.
Accepted manuscripts
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