Primary outcome measures and responder rates
| Numeric Rating Scale pain score | |||||||||
| Baseline | P value* | 1-month follow-up | P value* | 3-month follow-up | P value* | ||||
| CRFA (n=105) | SMM (n=105) | CRFA (n=94) | SMM (n=95) | CRFA (n=86) | SMM (n=92) | ||||
| Usual level of pain | |||||||||
| Mean (SD) | 6.3 (±1.4) | 6.3 (±1.4) | 0.91 | 4.1 (±2.4) | 5.2 (±1.9) | <0.001 | 3.8 (±2.4) | 5.9 (±1.7) | <0.0001 |
| Change from baseline in usual level of pain | |||||||||
| Mean (SD) | 2.3 (±2.1) | 1.1 (±2.0) | <0.001 | 2.5 (±2.5) | 0.4 (±1.7) | <0.0001 | |||
| Responder rate (≥30% or 2-point decrease in average NRS pain score+a score ≥5/7 on PGIC) (%) | (41.5) | (14.7) | <0.0001 | (52.3) | (4.3) | <0.0001 | |||
| Subjects reporting ≥50% pain relief (%) | (39.4) | (13.7) | <0.0001 | (41.9) | (6.5) | <0.0001 | |||
| SF-36 Physical Component Summary score | |||||||||
| Baseline | P value* | 1-month follow-up | P value* | 3-month follow-up | P value* | ||||
| CRFA† | SMM | CRFA | SMM‡ | CRFA§ | SMM | ||||
| Mean (SD) | 33.6 (±7.8) | 32.2 (±6.4) | 0.15 | 38.4 (±9.1) | 34.3 (±7.5) | <0.01 | 40.2 (±9.0) | 33.0 (±6.8) | <0.0001 |
| Oswestry Disability Index (ODI) | |||||||||
| Baseline | P value* | 1-month follow-up | P value* | 3-month follow-up | P value* | ||||
| CRFA | SMM | CRFA | SMM | CRFA§ | SMM | ||||
| Mean (SD) | 40.7 (±13.8) | 43.7 (±13.9) | 0.27 | 32.0 (±16.7) | 38.8 (±14.8) | <0.01 | 29.7 (±15.2) | 41.5 (±13.6) | <0.0001 |
| EQ-5D-5L index score | |||||||||
| Baseline | P value* | 1-month follow-up | P value* | 3-month follow-up | P value* | ||||
| CRFA¶ | SMM | CRFA | SMM | CRFA§ | SMM | ||||
| Mean (SD) | 0.48 (±0.27) | 0.46 (±0.27) | 0.53 | 0.65 (±0.25) | 0.53 (±0.26) | <0.001 | 0.68 (±0.22) | 0.47 (±0.29) | <0.0001 |
| Patient Global Impression of Change (PGIC) | ||||
| 1-month follow-up | 3-month follow-up | |||
| CRFA** | SMM‡ | CRFA§ | SMM | |
| Worse pain, no change or almost the same (combined PGIC scores of 1, 2 and 3) (%) | (23.6) | (62.1) | (21.8) | (64.1) |
| A little better or somewhat better, but change has not made any real difference (PGIC score of 4) (%) | (20.5) | (20.0) | (12.6) | (29.3) |
| Moderately better, and a slight but noticeable change (PGIC score of 5) (%) | (18.3) | (6.3) | (20.7) | (4.3) |
| Better and a definite improvement that has made a real and worthwhile difference (PGIC score of 6) (%) | (22.6) | (7.4) | (26.4) | (0.0) |
| A great deal better and a considerable improvement that has made all the difference (PGIC score of 7) (%) | (15.1) | (4.2) | (18.4) | (2.2) |
| Patients reporting improved PGIC score (%)** | |||||
| 1-month follow-up | P value* | 3-month follow-up | P value* | ||
| CRFA†† | SMM | CRFA§ | SMM | ||
| (55.9) | (17.9) | <0.0001 | (65.5) | (6.5) | <0.0001 |
*P values are reported between groups.
†(n=104).
‡(n=94).
§(n=87).
¶(n=103).
**Improved PGIC score defined as ≥5/7.
††(n=93).
CRFA, cooled radiofrequency ablation; NRS, Numeric Rating Scale; SF-36, 36-Item Short Form Survey; SMM, standard medical management.