Table 2. Postherpetic neuralgia pain scores at week-12 (primary outcomes) and week-6 (secondary outcome) in the two groups.
| Gabapentin n/N (%) |
Placebo n/N (%) |
OR (95% CI)* | p-Value | Gabapentin >300 mg/day n/N (%) |
Placebo | OR (95% CI)* >300 mg/day n/N (%) |
p-Value | ITT analysis Imputed OR (95% CI) |
p-Value | |
|---|---|---|---|---|---|---|---|---|---|---|
| Primary outcomes | ||||||||||
| Pain VAS > 0 at week-12 | 6/33 (18.2) | 4/42 (9.5) | 2.59 (0.59–11.28) | 0.144 | 3/24 (12.5) | 3/32 (9.4) | 1.58 (0.25–10.02) | 0.627 | 2.61 (0.43–15.8) | 0.283 |
| Pain VAS ≥ 4 at week-12 | 4/33 (12.1) | 0/42 (0) | N/A | N/A | 2/24 (8.3) | 0/32 (0) | N/A | N/A | N/A | N/A |
| DN-4 ≥4 at week-12 | 4/32 (12.5) | 3/37 (8.1) | 1.55 (0.28–8, 61) | 0.827 | 2/24(8.3) | 3/29 (10.3) | 0.74 (0.10–5.30) | 0.740 | 1.54 (0.23–10.4) | 0.735 |
| Secondary outcome | ||||||||||
| Pain VAS > 0 at week-6 | 10/33 (30.3) | 6/40 (15.0) | 1.94 (0.57–6.53) | 0.287 | 6/24 (25.0%) | 3/32 (9.4) | 2.8 (0.56–14.56) | 0.205 | 2.42 (0.63–9.25) | 0.188 |
Abbreviations: OR: odd ratio; 95% CI: 95% confidence interval; ITT: intention to treat; VAS: visual analogic scale; DN4: Doleur Neuropathique in 4 Questions.
*Adjusted by age, sex, and herpes zoster location.