Trends Over Time in the Use, Carbon Footprint and Costs of Facet Joint Injections and Medial Branch Blocks to Manage Lumbar Pain in England: Retrospective Analysis of an Administrative Dataset

Study design: Retrospective analysis of an administrative dataset. Objective: This study aims to investigate changing practice over a six-year period in the use of repeated lumbar facet joint injections/medial branch blocks in England. Methods: Patient data were extracted from the Hospital Episodes Statistics database for the period 1st April 2015 to 31st March 2021 for the index lumbar injection and for repeat lumbar injections performed within one year of the first. The exposure of interest was two injections within 180 days or three within one year. Patients aged < 17 years and where the body site was listed as cervical, thoracic or sacral were excluded. Results: Data were available for 134,249 patients of which, 8,922 (6.6%) had either two injections within 180 days or three injections within one year. First injections fell from 42,511 in 2015/16 to 13,368 in 2019/20 as did the number of repeat injections: 4,018 to 424 for the same period. If all years had the same carbon footprint as 2019/20, 2.8 kilotons of CO(2)e would have been saved over the five years, enough to power 2,575 average UK homes for 1 year. The financial cost of injections decreased from 27.6 pound million in 2015/16 to 7.9 pound million in 2019/20. Conclusions: The number of patients having repeated lumbar injections has decreased over time but has not been eliminated. More work is needed to educate patients and clinicians regarding alternative and more effective treatments.