Table 2

Summary of residual and phantom limb pain

PNS therapyPlacebo†
Full analysisPer protocolFull analysisPer protocol
Average RLP, mean (SD, n)
 Baseline score: diary average‡6.4 (1.0, 7)6.4 (1.2, 5)6.4 (1.3, 11)6.5 (1.4, 10)
 Baseline score: BPI-5‡6.3 (1.0, 7)6.4 (0.9, 5)5.9 (1.8, 11)6.0 (1.8, 10)
Average RLP: reduction from baseline, mean (SD, n), %
 Weeks 1–433 (43, 7)48 (43, 5)25 (22, 11)28 (22, 10)
 Weeks 5–836 (32, 7)48 (29, 5)27 (28, 11)30 (28, 10)
 Month 364 (24, 5)*64 (24, 5)*33 (43, 8)18 (43, 8)
 Month 486 (16, 4)**86 (16, 4)**16 (49, 7)16 (49, 7)
 Month 561 (30, 5)*61 (30, 5)*31 (40, 6)31 (40, 6)
 Month 637 (29, 4)37 (29, 4)−3 (28, 6)−3 (28, 6)
 Month 762 (30, 4)62 (30, 4)0 (20, 5)0 (20, 5)
 Month 886 (20, 2)86 (20, 2)2 (17, 4)2 (17, 4)
 Month 993 (10, 2)93 (10, 2)−17 (17, 3)−17 (17, 3)
 Month 1093 (10, 2)93 (10, 2)−6 (10, 3)−6 (10, 3)
 Month 1193 (10, 2)93 (10, 2)−8 (12, 2)−8 (12, 2)
 Month 1286 (0, 1)86 (0, 1)0 (0, 2)0 (0, 2)
Average PLP, mean (SD, n)
 Baseline score: diary average‡6.9 (1.7, 11)6.6 (1.5, 10)6.8 (1.7, 13)6.8 (1.7, 13)
 Baseline score: BPI-5‡6.4 (1.2, 11)6.4 (1.3, 10)6.5 (2.0, 13)6.5 (2.0, 13)
Average PLP: reduction from baseline, mean (SD, n), %
 Weeks 1–451 (24, 11)56 (19, 10)*23 (24, 13)23 (24, 13)
 Weeks 5–856 (33, 11)*62 (28, 10)**33 (28, 13)*33 (28, 13)*
 Month 358 (36, 10)*58 (36, 10)*23 (29, 10)23 (29, 10)
 Month 466 (31, 8)**66 (31, 8)**29 (21, 8)*29 (21, 8)*
 Month 555 (36, 9)55 (36, 9)28 (21, 7)28 (21, 7)
 Month 641 (36, 8)41 (36, 8)9 (24, 7)9 (24, 7)
 Month 763 (32, 8)63 (32, 6)5 (35, 5)5 (35, 5)
 Month 861 (40, 6)61 (40, 6)−5 (26, 4)−5 (26, 4)
 Month 961 (40, 6)61 (40, 6)−2 (31, 3)−2 (31, 3)
 Month 1066 (39, 5)66 (39, 5)3 (38, 3)3 (38, 3)
 Month 1166 (39, 5)66 (39, 5)−17 (24, 2)−17 (24, 2)
 Month 1255 (48, 5)55 (48, 5)14 (20, 2)14 (20, 2)
  • Follow-up is ongoing; data are as observed in months 7–12.

  • *P<0.05, **p<0.01, vs placebo group at the end of the placebo period.

  • †Placebo group received active stimulation during weeks 5–8.

  • ‡Measured by daily pain diaries during weeks 1–8, then by BPI-SF during follow-up.

  • BPI-SF, Brief Pain Inventory Short Form; PLP, phantom limb pain; PNS, peripheral nerve stimulation; RLP, residual limb pain.