Table 4.
Visual Analog Scale (VAS) between arm results
| Visual Analog Scale (VAS) | Basivertebral nerve ablation arm (N=66) |
Standard care arm (N=74) |
LS mean difference between arms |
P value |
| Baseline VAS | ||||
| Mean, SD (range) | 6.7, 1.3 (4–10) | 6.9, 1.3 (4–10) | 0.61* | |
| 3-Month VAS | n=66† | n=51† | ||
| Mean, SD (rRange) | 3.2, 2.7 (0 to –10) | 5.8, 2.2 (0 to –10) | ||
| Mean change from baseline, SD | –3.5, 2.6 | –1.1, 2.1 | ||
| LS mMean change (95% CI) | –3.5 (–4.1, to –3.0) | –1.0 (–1.7, to –0.4) | −2.5 (–3.4, to –1.6) | <0.001‡ |
| 6-Month VAS | n=60† | n=70§ | ||
| Mean, SD (Rrange) | 3.1, 2.4 (0 to –8) | 6.5, 1.8 (1 to –10) | ||
| Mean change from baseline, SD | –3.5, 2.5 | –0.4, 1.9 | ||
| LS Mmean change (95% CI) | –3.6 (–4.1, to –3.1) | –0.3 (–0.8, to 0.2) | −3.3 (–4.0, to –2.6) | <0.001‡ |
| 3-Month VAS responder rates | n=66† | n=51† | ||
| ≥2 cm reduction, n (%) | 48 (72.7%) | 17 (33.3%) | <0.001¶ | |
| 6-Month VAS responder rates | n=60† | n=70§ | ||
| ≥2 cm reduction, n (%) | 45 (75.0%) | 12 (17.1%) | <0.001¶ |
Secondary outcome measures for this study included the difference in least squares (LS) mean change in VAS between the basivertebral nerve (BVN) ablation arm and the standard care arm. Significant differences in LS mean VAS reductions and responder rates (using a minimal clinically important difference of ≥2 cm reduction) were observed at both 3 and 6 months.
*P value from a two-sample t-test with a factor of treatment group. Testing between randomized arms.
†As observed, with no imputation for missing data.
‡Estimates and p value from an ANCOVA with a factor of treatment group and a covariate of baseline VAS score.
§Standard care control arm 6-month last attended visit (median of 176.5 days). No imputations for missing data.
¶P value from a Fisher’s exact test.
LS, least squares; VAS, Visual Analog Scale.