Inter-rater agreement of the Pain and Disability Drivers Management rating scale

A framework to establish the biopsychosocial patient profile for persons with low back pain has been recently proposed and validated: The Pain and Disability Drivers Management model (PDDM). In order to facilitate its clinical integration, we developed the PDDM rating scale.

To determine the inter-rater agreement of the PDDM rating scale. A second objective was to determine if this inter-rater agreement varies according to the complexity of patients' clinical presentation.

We recruited physiotherapists during one-day workshops on the PDDM. We asked each participant to assess two clinical vignettes using the rating scale. One vignette presented a typical clinical presentation (moderate level of difficulty) and one presented an atypical presentation (complex level of difficulty). We determined inter-rater agreement with the proportion of participants who gave the same answer for each PDDM domain.

For the typical vignette, the inter-rater agreement per domain was moderate to good (between 0.54 and 0.97). For the complex vignette, the inter-rater agreement per domain was poor to good (between 0.49 and 0.81). The comparison between the two vignettes showed a significant difference (p< 0.01) for nociceptive and cognitive-emotional domains.

Overall performance indicates that the rating scale present adequate agreement for clinical use, but specific domains require further development.