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

Background An ever-increasing technological development in the field of radiology urges a need for guidelines to provide predictable and just health services. A musculoskeletal guideline was developed in Norway in 2014, without active implementation. Purpose To investigate the impact of active guideline implementation on the use of musculoskeletal diagnostic imaging most frequently encountered in general practice (pain in the neck, shoulders, lower back, and knees). Material and Methods The total number of outpatient radiological examinations across modalities registered at the Norwegian Health Economics Administration between January 2013 and February 2019 was assessed using an interrupted time series design. Results A 12% reduction in the total examination of Magnetic Resonance Imaging shoulder and knee, and x-ray lower back and shoulder was found at a significant level (p = 0.05). Stratified analysis (Magnetic Resonance Imaging examination as one group and x-ray examinations as the other) showed that this reduction mainly was due to the reduction in the use of Magnetic Resonance Imaging examinations (shoulder and knee) which was reduced by 24% at a significant level (p = 0.002), while x-ray examinations had no significant level change (p = 0.71). No other statistically significant changes were found. Conclusion 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.