Relationship of pain relief with catastrophizing following interventional pain procedures for low back pain.

INTRODUCTION

Catastrophizing is associated with worse pain outcomes after various procedures suggesting its utility in predicting response. However, the stability of pain catastrophizing as a static predictor has been challenged. We assess, among patients undergoing steroid injections for chronic low back pain (cLBP), whether catastrophizing changes with the clinical response to pain interventions.

METHODS

This prospective study enrolled patients undergoing fluoroscopic-guided injections for cLBP. Patients filled out Brief Pain Inventory (BPI) and Pain Catastrophizing Scale (PCS) at baseline and 1-month follow-up. We assessed the change in PCS scores from pre-injection to post-injection and examined its predictors. We also examined the correlation of various domains of BPI, such as pain severity and effect on Relationships, Enjoyment, and Mood (REM), with PCS scores at baseline and follow-up.

RESULTS

128 patients were enrolled. Mean (SD) PCS and pain severity scores at baseline were 22.38 (±13.58) and 5.56 (±1.82), respectively. Follow-up PCS and pain severity scores were 19.76 (±15.25) and 4.42 (±2.38), respectively. The change in PCS pre-injection to post-injection was not significant (p=0.12). Multiple regression models revealed baseline PCS and REM domain of BPI as the most important predictors of change in PCS after injection. Pain severity, activity-related pain, age, sex, insurance status, depression, prior surgery, opioid use, or prior interventions did not predict change in PCS score. In correlation analysis, change in PCS was moderately correlated with change in pain (r=0.38), but weakly correlated with baseline pain in all pain domains.

CONCLUSIONS

PCS showed non-significant improvement following steroid injections; the study was not powered for this outcome. Follow-up PCS scores were predicted by the REM domain of BPI, rather than pain severity. Larger studies are needed to evaluate a statistically significant and clinically meaningful change in catastrophizing scores following pain interventions.