Geographical variations in the use of diagnostic imaging of musculoskeletal diseases in Norway

Abstract

Background: There is a high prevalence of musculoskeletal disorders in the Norwegian population. A significant number of these patients are referred to diagnostic imaging. Geographical variations in the use of imaging for musculoskeletal disorders may display over- or underuse, and knowledge about these variations is required. Purpose: To investigate geographical variations in diagnostic imaging of the musculoskeletal system and analyze variations in the use of these examinations of all musculoskeletal diagnostic imaging, the specific modalities, and specific examinations. Material and Methods: Population rates from Statistics Norway and outpatient radiological procedures of the musculoskeletal system registered at the Norwegian Health Economics Administration (HELFO) the first half of 2016 were accessed. The HELFO data were age-adjusted; high/low ratios were calculated as rates in number of examinations per 1000 inhabitants. A high/low ratio of 1 ¼ equal use, 1.5–1.9 ¼ moderate variation (approximately 50% difference), and > 2 (twice as much) ¼ high variation. Results: Geographical variations were demonstrated at all levels, with an overall high/low ratio of 1.3. For specific modalities the highest variation was for ultrasound (3.2) and CT (2.2). For individual examinations, the highest high/low ratios were observed for MRI of the shoulder (2.4) and radiography of the lower back (1.9) and shoulder (1.8). Conclusion: We demonstrate a moderate to high geographical variation in the use of diagnostic imaging of the musculoskeletal system. This variation can indicate over- or underuse, which may violate basic principles of equity, priority, setting and appropriate care, and needs further attention.