Belgian multicentre study on lumbar spine imaging: Radiation dose and cost analysis; Evaluation of compliance with recommendations for efficient use of medical imaging.

Purpose: To assess compliance of lumbar spine imaging referrals with national imaging recommendations and to evaluate the impact of inappropriate imaging on the collective radiation dose and health insurance costs.

Method: In 2011 and 2015, 633 lumbar spine imaging referrals were evaluated across 9 Belgian hospitals. For each patient, a new clinical anamnesis and physical examination were performed. Together with the referral, this data were confronted with the national imaging recommendations. Collective radiation dose was estimated for the radiography and CT procedures. Cost analysis was based on national reimbursement fees. Statistical analysis was performed using multilevel linear and logistic regression models.

Results: The fraction of unjustified imaging referrals decreased from 50 % in 2011 to 41 % in 2015 (p = 0.255). The odds of a justified examination are 3.1 times higher when the referral is done by a specialist instead of a general practitioner. The highest percentage of unjustified examinations was found for CT (85 % in 2011, 81 % in 2015; p = 0.044). Seventy-five percent of the collective dose of both the 2011 and the 2015 study population was not justified. Adherence to the recommendations could result in an estimated 16 % and 5 % cost reduction for the 2011 and 2015 study samples, respectively.

Conclusions: Between 2011 and 2015, no significant improvement was found in requesting justified lumbar spine imaging procedures, although a positive trend was observed for CT. A shift from CT to MRI is necessary to improve the appropriateness of lumbar spine imaging referrals and to reduce the collective radiation dose.