Validity of the French version of the Core Outcome Measures Index for low back pain patients: a prospective cohort study

Purpose: Among the many questionnaires available to evaluate low back pain (LBP) patients, the Core Outcome Measures Index (COMI) has the unique advantage to investigate five dimensions using seven short questions. The aim of this study was to explore additional properties of the questionnaire in a French-speaking non-surgical population. Methods: This study was conducted on 168 patients suffering from subacute or chronic LBP and followed up for 6months in three French-speaking countries. In addition to basic psychometric properties (e.g., construct validity, floor and ceiling effect, reproducibility), internal validity was analyzed by a factor analysis using Cronbach's alpha. Responsiveness and sensitivity to change were assessed through minimal detectable change (MDC), effect size, and Minimal Clinically Important Improvement (MCII). We used an anchor-based method with receiver operating characteristic (ROC) curve analysis to assess MCII and the Patient Acceptable Symptom State. Results: Construct validity, reliability (Cronbach's alpha=0.87), reproducibility and the absence of floor and ceiling effects were confirmed. Factor analysis indicated a one-dimensional construct that validates the use of a sum score. The MDC (2.1) was inferior to the MCII (2.3). The limit below which the patient claims to be in a fair condition (Patient Acceptable Symptom State) was set at 3. Conclusions: The COMI is a self-report questionnaire with the capacity to easily and quickly explore several dimensions in patients with LBP that can be then summarized in a meaningful sum score. Additional knowledge provided by our study should encourage the widespread use of the COMI among the spine community

Intérêt du Start Back Screening Tool pour les médecins généralistes

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Are the back educational interventions effective for preventing low back pain

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The maladaptive beliefs of patients with low back pain: a narrative review

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Prise en charge des patients lombalgiques : les mots du thérapeute aussi importants que ses mains

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Inter-session, inter-tester and inter-site reproducibility of isometric trunk muscle strength measurements

The purpose of this study was to investigate the inter-session, inter-tester and inter-site reproducibility of trunk muscle strength scores in flexion, extension, lateral flexion and rotation. Ten healthy students were tested on four apparatus with a 7-10 day break between sessions. The first two sessions were identical while the other two differed either by the tester or by the site. Furthermore, 10 patients with chronic low back dysfunction (CLBD) were assessed with the four apparatus, once only. For all tests, CV ranged from 3.4% to 7.6% and from 3.9% to 8.1% in the inter-session and inter-tester studies, respectively (p > 0.05 except for inter-session reproducibility of trunk flexor strength). Peak torque (PT) was more variable from site to site with a CV ranging from 4.2% to 12.7%, particularly in extension and left lateral flexion (p < 0.05). No statistically significant difference in the strength ratios (flexion/extension, right/left lateral-flexion and right/left rotation) were found between sessions or testers (4.9% < CV < 9.7%). The inter-site reproducibility of ratios was lower. Comparison between the CLBD patients and the healthy subjects with regard to PT normalized to body weight indicated significantly decreased performance for the former except for flexion and rotation scores in males. We conclude that in the case of healthy subjects, inter-session and inter-tester trunk strength measurements derived from these devices are reproducible. The low inter-site reproducibility suggests that caution should be exercised when interpreting findings originating from different sites. The lower extension strength scores in CLBD patients test lends some validity to the system. However, further studies focusing on reproducibility and validity of this system in CLBD patients are critical before any conclusion regarding their clinical viability may be drawn