Physical therapists' level of McKenzie education, functional outcomes, and utilization in patients with low back pain.

Study Design: Longitudinal, prospective, observational cohort.

Objective: To examine associations between McKenzie training, functional status (FS) at discharge, and number of physical therapy visits (utilization) in patients receiving physical therapy for low back pain.

Background: The McKenzie method is commonly used in treating patients with low back pain.

Methods: A McKenzie postgraduate educational program was initiated in a large outpatient physical therapy service. Functional status data were collected at intake and at discharge. Separate hierarchical linear mixed models were used to examine associations between physical therapists' McKenzie training level (none; Parts A, B, C, and D; and credentialed), FS score at discharge, and utilization, controlling for patient risk factors.

Results: The final data set included 20 882 patients (mean ± SD age, 51 ± 16 years; 57% women) who completed FS surveys at both admission and discharge. Patients treated by physical therapists with any McKenzie training had better outcomes (additional 0.7 to 1.3 FS points; P<.05 to <.001) and fewer visits (0.6 to 0.9, P<.001) compared to patients treated by physical therapists with no training. For patients treated by therapists with no versus some McKenzie education, 65% versus 70% achieved at least the minimal clinically important improvement, respectively. There were no significant differences in outcomes or utilization by level of McKenzie training.

Conclusion: There was a slightly greater improvement of 0.7 to 1.3 points in FS at discharge in patients receiving physical therapy for low back pain by physical therapists who underwent McKenzie training. This difference was clinically important for an additional 5% of patients who achieved the minimal clinically important improvement when treated by therapists with some McKenzie training. Reduction in physical therapy utilization was 0.6 to 0.9 visits, with the fewest visits utilized by patients of physical therapists at the McKenzie Part D and credentialed levels. Together, these findings suggest improved cost-effectiveness at advanced McKenzie training levels. Ways to improve ongoing education and patient outcomes were proposed.