The mechanical and inflammatory low back pain (MIL) index: development and validation.

Abstract

BACKGROUND:

The purpose of this study was the development of a valid and reliable "Mechanical and Inflammatory Low Back Pain Index" (MIL) for assessment of non-specific low back pain (NSLBP). This 7-item tool assists practitioners in determining whether symptoms are predominantly mechanical or inflammatory.

METHODS:

Participants (n = 170, 96 females, age = 38 ± 14 years-old) with NSLP were referred to two Spanish physiotherapy clinics and completed the MIL and the following measures: the Roland Morris Questionnaire (RMQ), SF-12 and "Backache Index" (BAI) physical assessment test. For test-retest reliability, 37 consecutive patients were assessed at baseline and three days later during a non-treatment period. Face and content validity, practical characteristics, factor analysis, internal consistency, discriminant validity and convergent validity were assessed from the full sample.

RESULTS:

A total of 27 potential items that had been identified for inclusion were subsequently reduced to 11 by an expert panel. Four items were then removed due to cross-loading under confirmatory factor analysis where a two-factor model yielded a good fit to the data (χ2 = 14.80, df = 13, p = 0.37, CFI = 0.98, and RMSEA = 0.029). The internal consistency was moderate (α = 0.68 for MLBP; 0.72 for ILBP), test-retest reliability high (ICC = 0.91; 95%CI = 0.88-0.93) and discriminant validity good for either MLBP (AUC = 0.74) and ILBP (AUC = 0.92). Convergent validity was demonstrated through similar but weak correlations between the ILBP and both the RMQ and BAI (r = 0.34, p < 0.001) and the MLBP and BAI (r = 0.38, p < 0.001).

CONCLUSIONS:

The MIL is a valid and reliable clinical tool for patients with NSLBP that discriminates between mechanical and inflammatory LBP.

• Authors: Antonio Cuesta-Vargas, Andre Farasyn, Charles Philip Gabel, Juan V Luciano
• Journal: BMC musculoskeletal disorders (BMC Musculoskelet Disord) Vol. 15 Pg. 12 (Jan 09 2014) ISSN: 1471-2474 [Electronic] England
• PMID: 24405779 (Publication Type: Journal Article, Multicenter Study, Observational Study, Research Support, Non-U.S. Gov't, Validation Study)

Topics

• Adult
• Area Under Curve
• Female
• Humans
• Inflammation (diagnosis, etiology, physiopathology)
• Low Back Pain (diagnosis, etiology, physiopathology)
• Male
• Middle Aged
• Observer Variation
• Pain Measurement (methods)
• Predictive Value of Tests
• Prospective Studies
• Psychometrics
• ROC Curve
• Reproducibility of Results
• Risk Factors
• Severity of Illness Index
• Spain
• Surveys and Questionnaires
• Young Adult