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 VASn=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 VASn=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 ratesn=66†n=51†
 ≥2 cm reduction, n (%)48 (72.7%)17 (33.3%)<0.001¶
6-Month VAS responder ratesn=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.