Inter-rater reliability of McKenzie assessment in patients with neck pain

Objectives

To determine inter-rater agreement on diagnostic category using the Mechanical Diagnosis and Therapy (MDT) classification system for neck pain. If the diagnostic category was derangement syndrome, inter-rater agreement on the subcategory and the directional preference of treatment was also determined.

Design

Clinicians viewed videotaped MDT examinations of 20 patients with neck pain and rated the MDT diagnosis independently for each patient. If the diagnostic category was derangement syndrome, the subcategory and directional preference of treatment were also rated.

Setting

Private physical therapy outpatient clinics and a university clinical laboratory.

Participants

Fifty-four clinicians trained in MDT for neck pain from the USA and Canada, and 20 adult patients with neck pain.

Main outcome measures

Inter-rater agreement for MDT diagnosis, derangement subcategory and directional preference of treatment was determined using Kappa and percentage agreement.

Results

Overall, agreement was of moderate clinical significance for diagnosis κ = 0.55, P < 0.001, confidence intervals (CI) 0.52 to 0.58, 67%], derangement subcategory (κ = 0.47, CI 0.44 to 0.50, P < 0.001; 63%) and directional preference of treatment (κ = 0.46, CI 0.43 to 0.49, P < 0.05; 70%).

Conclusions

Clinicians trained in MDT for neck pain demonstrate moderate agreement when classifying the diagnostic category and treatment for neck pain.