Roland-Morris disability questionnaire is bidimensional and has 16 items when applied to community-dwelling older adults with low back pain

Abstract

Purpose

To explore the evidence of the internal structure validity of the Roland-Morris Disability Questionnaire in older adults with low back pain.

Methods

This was a cross-sectional study of psychometric testing involving 528 older adults with low back pain. Internal structure validity was explored by exploratory factor analysis and semi-confirmatory factor analysis. Reliability was verified using Kuder-Richardson Formula 20, Cronbach’s alpha, and McDonald’s omega. Replicability was observed by the generalized H index.

Results

Roland-Morris Disability Questionnaire displayed two factors that assess “functional capacity” and “mobility”. Eight items were excluded for presenting cross-loading (2 and 10), inadequate loading factors and communalities (18, 24, 13, and 12), or did not relate to the latent construct (15 and 22). Semi-confirmatory factor analysis indicated that the questionnaire had a good fitness model [X² = 153.698 (p = 0.00001); RMSEA = 0.037; RMSR = 0.06; WRMR = 0.04; NNFI = 0.987; GFI = 0.979; AGFI = 0.971]. Reliability was acceptable (KR-20 = 0.79; Cronbach’s alpha = 0.86; McDonald’s Omega = 0.85), but replicability was poor in both factors (G-H factor 1 = 0.816–0.655; G-H factor 2 = 0.889–0.775).

Conclusions

The most appropriate version of the Roland-Morris Disability Questionnaire to apply to older adults with low back pain has 16 items and assesses functional capacity and mobility.

IMPLICATIONS FOR REHABILITATION

• The RMDQ-16 is the most appropriate version of the RMDQ to use in older adults with LBP;

• The RMDQ-16 is bidimensional and assesses “functional capacity” and “mobility”;

• The poor replicability of the RMDQ-16 indicates that it will probably not be stable across studies, but it can be useful in a clinical setting.

Keywords:

• Low back pain
• chronic pain
• aged adult
• disability evaluation
• validation study
• psychometrics
• self-assessment

Acknowledgment

The authors would like to thank all the sites which provided support for data collection: Centro de Referência do Idoso Norte; Ambulatório Médico de Especialidades Idoso Oeste, and Liga Solidária.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.