Responses after spinal interventions in a clinical pain practice – a pragmatic observational study
Authors: Måwe Leif , Thorén Lena Måwe , Kvarstein Gunnvald 
Published: January 2020

Abstract

Introduction
There is limited evidence for effect of interventional treatment, and pragmatic studies are needed to assess these interventions within a clinical setting. The aim of this study was to describe patients referred to an interventional pain clinic and investigate responses after spinal intervention in general and for radiofrequency ablation (RFA) and transforaminal epidural corticosteroid administration (TECA), specifically.

Methods
This is a prospective, non-controlled study of patients with chronic spinal pain. The procedures were performed in accordance with the Spine Intervention Society recommendations. Outcome data after a median of 4.5 months are presented, and for those treated with RFA also after 6 and 12 months.

Results
Among 815 patients, 190 patients underwent diagnostic blocks only and 625 interventional treatment, of these 94 RFA and 246 TECA. Of the whole sample 70% reported pain reduction, for 49% ≥ 50%, while 9% were pain free (p < 0.001). Highest pain intensity decreased from 7.1 to 5.4 [95% Confidence Interval of the Difference (95%-CI): 1.4–1.9] (p < 0.001), while Euroqual – visual analogue scale for general health (EQ-VAS) improved from 48 to 58 (95%-CI: 7.6–11.9) (p < 0.001), and Euroqual-5 Dimensions-5 Levels Index for health related quality of life (EQ-5D-5L Index) from 0.489 to 0.628 (95%-CI: 0.123–0.157) (p < 0.001). The proportions, not taking analgesics, increased from 16% to 30%, and proportion taking strong opioids decreased from 14% to 9% (p < 0.001). We found no significant change in proportion receiving physiotherapy/other treatment nor occupational status. No complications were reported. Among patients treated with RFA, 77% reported pain reduction, for 56% ≥ 50%, while 9% were pain free (p < 0.001). Highest pain intensity decreased from 6.9 to 4.6 (95%-CI: 1.6–3.0) (p < 0.001), while EQ-VAS improved from 47 to 57 (95%-CI: 4.8–13.6 (p < 0.001), and EQ-5D-5L Index from 0.489 to 0.643 (95%-CI: 0.117–0.191) (p < 0.001). The proportion not taking analgesics, increased from 7% to 23% and proportion taking strong opioids decreased from 16% to 10%. Among patients who responded at 6- and 12-month follow up, the proportions reporting pain reduction, EQ-VAS, and EQ-5D-5L Index remained significantly improved from baseline, and the change in proportions taking analgesic and opioids achieved statistical significance. We found no significant change in proportion receiving physiotherapy/other treatment nor occupational status. Among patients treated with TECA, 58% reported pain reduction, for 36% ≥ 50%, while 5% were pain free (p < 0.001). Highest pain intensity decreased from 7.2 to 6.2 (95%-CI 0.5–1.4) (p < 0.001), while EQ-VAS improved from 46 to 52 (95%-CI: 2.0–3.6) (p < 0.001), and EQ-5D-5L Index from 0.456 to 0.571 (95%-CI: 0.077–0.138) (p < 0.001). The proportions, not taking analgesics, increased from 17% to 27% and proportion taking strong opioids decreased from 15% to 10%, but the changes did not reach statistical significance. We found no significant changes in the proportion who recieved physiotherapy/other treatment nor occupational status.

Conclusion
The study demonstrates substantial short-term responses after spinal intervention and long-lasting improvement for a subsample of the RFA treated patients. We observed larger proportions reporting pain reduction among those treated with cervical RFA.

Implementation
Quality assessment should be implemented in interventional pain clinics to improve treatment quality.