[Comparison of pain intensity measurements among patients with low-back pain]. / A fájdalom intenzitását méro skálák összehasonlítása ágyéki gerincfájdalommal élok körében.

Background and purpose:

Pain intensity is the most frequently assessed health domain in clinical studies among patients with low-back pain. Visual analogue scale (VAS) and Numeric rating scale (NRS) have been the mostly used measurement tools for pain intensity. We proposed to correlate these instruments to a generic health-related quality of life measurement tool in order to show the scale with superior clinical relevance.

We used cross-sectional, convenience sampling. 120 patients with chronic low-back pain administered the 29-item Patient Reported Outcomes Measurement Information System Profile with NRS included, and the VAS scale in the National Institute of Mental Health, Neurology and Neurosurgery. We determined the correlation between PROMIS domain T-scores and VAS and NRS scores.

We performed Spearman rank correlation test to calculate the correlation coefficient. We found VAS scales measuring pain had weak to moderate correlations with all PROMIS health domains (r = 0.24–0.55). Therefore, we compared correlation of PROMIS domain scores with PROMIS pain intensity numeric rating scale and VAS scales. PROMIS domains had moderate to strong correlations with pain intensity scale (r = 0.45–0.71). PROMIS physical function short form [r = –0.65, 95% CI (–0.75) – (–0.55)] and PROMIS pain interference short form (r = 0.71, 95% CI 0.63 – 0.79) had the strongest correlation with pain intensity item.

NRS has showed greater correlation with PROMIS domain T-scores than VAS scale. This may prove that NRS has greater connection to another health domains, thus it correlated more to health-related quality of life than visual scale. We recommend NRS to use in further clinical studies conducted among patients with low-back pain.

Construct validity of the Hungarian Version of the Patient-Reported Outcomes Measurement Information System-29 Profile Among Patients with Low Back Pain.

OBJECTIVE: We aim to evaluate the psychometric properties of the Hungarian version of the patient-reported outcomes measurement information system (PROMIS)-29 profile domains among patients with chronic low back pain. METHODS: We used a convenience, cross-sectional sampling of patients recruited at our neurosurgical institution. The participants completed paper-pencil version of the PROMIS-29 profile in addition to validated legacy questionnaires, including the Oswestry disability index, Research and Development Corporation 36-item short-form survey, 7-item general anxiety disorder scale, 9-item patient health questionnaire. Reliability was evaluated by calculating the internal consistency (Cronbach's α). Test-retest reliability was assessed using the intraclass correlation coefficient. The structural validity of PROMIS-29 was assessed using a confirmatory factor analysis. Construct validity was assessed by evaluating convergent and discriminant validity using Spearman's rank correlation. To further corroborate the construct validity, we also performed known-group comparisons. RESULTS: The mean age of the 131 participants was 54 ± 16 years. Of the 131 patients, 62% were women. The internal consistency of each PROMIS domain was high (Cronbach's α >0.89 for all). The test-retest reliability was excellent (intraclass correlation >0.97). The confirmatory factor analysis showed good structural validity (comparative fit index >0.96; standardized root mean square residual <0.026 for all domains). All measured PROMIS scores correlated strongly with the scores obtained using the corresponding primary legacy instrument, indicating excellent convergent validity. The known-group comparisons demonstrated differences as hypothesized. CONCLUSIONS: We present data supporting the validity and reliability of the Hungarian PROMIS-29 profile short forms for patients with low back pain. This instrument will be useful for research and clinical applications in spine care.