Impact on radiological practice of active guideline implementation of musculoskeletal guideline, as measured over a 12-month period.

The impact of the implementation on the use of imaging of the neck, shoulder, lower back, and knee is uncertain. Significant reductions were demonstrated in the use of some examinations in the intervention county, but similar effects were not seen when including a control group in the analysis. This indicates a diffusion of the implementation, or other interventions or events that affected both counties and occurred in the intervention period.