Trends in public sector radiological usage in the Western Cape Province, South Africa: 2009-2019.

Background: Although global use of medical imaging has increased significantly, little is known about utilisation trends in low- and middle-income countries (LMICs).

Objectives: To evaluate changes over a decade in public sector diagnostic imaging utilisation at provincial level in a middle-income country.

Method: A retrospective analysis of medical imaging utilisation in the Western Cape Province of South Africa in 2009 and 2019. Use of conventional radiography, ultrasonography (US), fluoroscopy, CT, MRI, digital subtraction angiography (DSA) and whole-body digital radiography was assessed by total studies and studies/10³ people, for the whole province, the rural and metropolitan areas. Mammography utilisation was calculated for every 10³ females aged 40-70 years.

Results: The provincial population and total imaging investigations increased by 25% and 32%, respectively, whilst studies/10³ people increased by 5.5% (256 vs 270/10³), with marked variation by modality. Provincial US, CT and MRI utilisation/10³ people increased by 111% (20 vs 43/10³), 78% (10 vs 18/10³) and 32% (1.9 vs 2.5/10³) respectively, whilst use of fluoroscopy (3.6 vs 3.7/10³) and mammography (14.2 vs 15.9/10³ women aged 40-70 years) was steady and plain radiography decreased by 20% (216 vs 196/10³). For CT, mammography and fluoroscopy, percentage utilisation increases/10³ people were higher in the rural than metropolitan areas.

Conclusion: Population growth is the main driver of overall imaging utilisation in our setting. The relatively constant imaging workload per 1000 people, albeit with increasing ultrasound, CT and MR utilisation, and decreasing use of plain radiography, reflects improved provincial imaging infrastructure, and appropriate use of available resources.