Table 2.
Main results in pregabalin trials
| Efficacy | % with | ||||
|---|---|---|---|---|---|
| Subgroup | Number of patients | Relative benefit (95% CI) | NNT (95% CI) | Placebo | Pregabalin |
| At least 50% pain relief | |||||
| All | 2430 | 2.4 (2.0, 2.8) | 5.2 (4.5, 6.4) | 14 | 33 |
| PEE | 1342 | 2.3 (1.6, 2.9) | 6.3 (4.9, 8.7) | 15 | 31 |
| NEE | 1088 | 2.4 (1.8, 3.3) | 4.4 (3.6, 5.6)a | 13 | 36 |
| 150 mg | 538 | 1.6 (1.0, 2.5) | 14 (7.3, 150) | 13 | 20 |
| 300 mg | 697 | 2.4 (1.7, 3.5) | 6.1 (4.4, 9.5)b | 13 | 30 |
| 600 mg | 1195 | 2.6 (3.0, 3.3) | 3.8 (3.2, 4.7)c | 16 | 42 |
| Patient global impression of change | |||||
| All | 1724 | 2.0 (1.6, 2.3) | 4.7 (3.9, 6.0) | 22 | 43 |
| PEE | 1018 | 2.1 (1.7, 2.6) | 4.3 (3.4, 5.8) | 22 | 45 |
| NEE | 706 | 1.8 (1.3, 2.4) | 5.3 (3.8, 9.1) | 22 | 41 |
| 150 mg | 416 | 1.5 (1.0, 2.2) | 11 (5.5, 350) | 20 | 29 |
| 300 mg | 549 | 2.1 (1.5, 2.9) | 4.8 (3.5, 7.7)d | 20 | 41 |
| 600 mg | 759 | 2.1 (1.6, 2.7) | 3.7 (2.9, 5.1)e | 25 | 52 |
| Lack of efficacy withdrawal | |||||
| All | 2174 | 0.36 (0.27, 0.49) | −12 (−19, −9.0) | 14 | 6 |
| PEE | 1085 | 0.33 (0.20, 0.54) | −18 (−45, −11) | 10 | 4 |
| NEE | 1089 | 0.38 (0.27, 0.53) | −8.4 (−14, −6.0)f | 20 | 8 |
| 150 mg | 538 | 0.55 (0.32, 0.95) | −23 (71, −10) | 12 | 8 |
| 300 mg | 568 | 0.39 (0.22, 0.72) | −20 (−750, −9.9) | 11 | 5 |
| 600 mg | 1068 | 0.28 (0.19, 0.42) | −8.4 (−14, −6.1)g | 18 | 6 |
| Harm | |||||
|---|---|---|---|---|---|
| with | |||||
| Subgroup | Number of patients | Relative risk (95% CI) | NNH (95% CI) | Placebo | Pregabalin |
| Adverse event withdrawal | |||||
| All | 2431 | 2.2 (1.6, 2.9) | 14 (10, 20) | 6 | 14 |
| PEE | 1343 | 2.2 (1.5, 3.2) | 16 (11, 30) | 6 | 12 |
| NEE | 1089 | 2.1 (1.4, 3.3) | 12 (8.3, 23) | 7 | 16 |
| 150 mg | 538 | 1.0 (0.52, 1.9) | 960 (20, −21) | 8 | 8 |
| 300 mg | 697 | 1.7 (1.0, 3.1) | 21 (11, 150) | 6 | 10 |
| 600 mg | 1197 | 3.0 (2.0, 4.5) | 8.3 (6.3, 12)h | 7 | 19 |
| Somnolence | |||||
| All | 2432 | 4.4 (3.2, 6.1) | 6.7 (5.8, 8.1) | 5 | 20 |
| PEE | 1343 | 4.4 (2.9, 6.7) | 5.6 (4.7, 7.0) | 5 | 23 |
| NEE | 1089 | 4.4 (2.6, 7.6) | 8.6 (6.6, 12)i | 5 | 16 |
| 150 mg | 538 | 2.0 (1.0, 4.1) | 16 (9.0, 73) | 6 | 12 |
| 300 mg | 697 | 4.9 (2.6, 9.2) | 5.8 (4.6, 7.9)j | 4 | 22 |
| 600 mg | 1197 | 5.4 (3.4, 8.7) | 5.7 (4.7, 7.2)k | 5 | 22 |
| Dizziness | |||||
| All | 2432 | 3.2 (2.5, 4.1) | 5.1 (4.4, 6.0) | 9 | 29 |
| PEE | 1343 | 2.9 (2.2, 3.9) | 4.9 (4.1, 6.2) | 11 | 31 |
| NEE | 1089 | 4.0 (2.6, 6.3) | 5.2 (4.3, 6.6) | 6 | 26 |
| 150 mg | 538 | 1.6 (0.96, 2.8) | 14 (7.8, 95) | 9 | 16 |
| 300 mg | 697 | 2.9 (1.9, 4.3) | 5.0 (3.9, 7.0)l | 11 | 31 |
| 600 mg | 1197 | 4.5 (3.1, 6.6) | 4.0 (3.4, 4.8)m | 8 | 33 |
NNT, number needed to treat. NNH, number needed to harm. 150 mg, 300 mg and 600 mg refer to the maximum daily doses of pregabalin allowed in the trials. For patient global impression of change after pregabalin treatment we display the results for subjects reporting ‘much or very much’ improvement, and the 600 mg subgroup contains data from one trial group [29] that used 450 mg as the maximum allowed daily dose of pregabalin. Lack of efficacy withdrawals also includes those described as ‘treatment failure’. Significant differences between treatment groups are labelled in the figure as follows: a) P = 0.044 for the comparison PEE vs. NEE, b) P = 0.040 for 150 mg vs. 300 mg, c) P < 0.00006 for 150 mg vs. 600 mg, d) P = 0.052 for 150 mg vs. 300 mg. e) P < 0.0027 for 150 mg vs. 600 mg. f) P = 0.036 for PEE vs. NEE. g) P = 0.039 for 150 mg vs. 600 mg. h) P < 0.00014 for 150 mg vs. 600 mg. i) P = 0.014 for PEE vs. NEE. j) P = 0.0014 for 150 mg vs. 300 mg. k) P < 0.00032 for 150 mg vs. 600 mg. l) P < 0.0019 for 150 mg vs. 300 mg. m) P < 0.00006 for 150 mg vs. 600 mg.