Table 7.
Reasons for withdrawal from allocated treatment
| Reason for withdrawal |
Classification for analysis |
Randomised drug4b | ||||||||||
| CBZ | PHB | PHT | VPS | LTG | OXC | TPM | GBP | LEV | ZNS | Total | ||
| Adverse events | Event | 505 (45%) | 24 (20%) | 93 (35%) | 132 (28%) | 235 (41%) | 56 (41%) | 259 (48%) | 73 (20%) | 134 (39%) | 31 (32%) | 1542 (38%) |
| Inadequate response | Event | 232 (20%) | 20 (16%) | 46 (17%) | 140 (29%) | 144 (26%) | 36 (26%) | 148 (27%) | 223 (62%) | 89 (26%) | 23 (24%) | 1101 (27%) |
| Both adverse events and inadequate response |
Event | 148 (13%) | 51 (41%) | 54 (20%) | 107 (22%) | 32 (6%) | 11 (8%) | 46 (8%) | 32 (9%) | 0 (0%) | 0 (0%) | 481 (12%) |
| Protocol violation/non compliance | Event | 102 (9%) | 15 (12%) | 41 (15%) | 11 (2%) | 68 (12%) | 27 (20%) | 0 (0%) | 21 (6%) | 21 (6%) | 3 (3%) | 309 (8%) |
| Withdrew consent | Event | 121 (11%) | 13 (11%) | 25 (9%) | 64 (13%) | 65 (11%) | 2 (1%) | 55 (10%) | 4 (1%) | 68 (20%) | 35 (36%) | 452 (11%) |
| Othera | Event | 29 (3%) | 0 (0%) | 7 (3%) | 24 (5%) | 26 (5%) | 5 (4%) | 37 (7%) | 9 (2%) | 32 (9%) | 4 (4%) | 173 (4%) |
| Total eventsb | 1137 (35%) | 123 (38%) | 266 (31%) | 478 (28%) | 570 (29%) | 137 (29%) | 545 (47%) | 362 (61%) | 344 (27%) | 96 (34%) | 4058 (34%) | |
| Illness or death | Censored | 34 (2%) | 10 (5%) | 17 (3%) | 7 (1%) | 20 (1%) | 1 (0%) | 10 (2%) | 9 (4%) | 0 (0%) | 0 (0%) | 108 (1%) |
| Remission of seizures | Censored | 49 (2%) | 4 (2%) | 38 (6%) | 75 (6%) | 40 (3%) | 12 (4%) | 44 (7%) | 21 (9%) | 0 (0%) | 0 (0%) | 283 (4%) |
| Lost to follow‐up | Censored | 81 (4%) | 31 (16%) | 51 (9%) | 63 (5%) | 33 (3%) | 24 (7%) | 18 (3%) | 0 (0%) | 41 (5%) | 0 (0%) | 342 (4%) |
| Otherc | Censored | 104 (5%) | 6 (3%) | 22 (4%) | 82 (7%) | 31 (2%) | 5 (2%) | 26 (4%) | 26 (12%) | 0 (0%) | 25 (13%) | 327 (4%) |
| Completed study | Censored | 1829 (87%) | 139 (73%) | 468 (79%) | 949 (81%) | 1272 (91%) | 291 (87%) | 501 (84%) | 166 (75%) | 868 (95%) | 161 (87%) | 6644 (86%) |
| Total censoredb | 2097 (65%) | 190 (62%) | 596 (69%) | 1176 (72%) | 1396 (71%) | 333 (71%) | 599 (53%) | 222 (39%) | 909 (73%) | 186 (66%) | 7704 (66%) | |
| Missingd | 24 | 7 | 1 | 26 | 12 | 8 | 14 | 11 | 0 | 0 | 103 | |
| Totale | 3258 | 320 | 863 | 1680 | 1978 | 478 | 1158 | 595 | 1253 | 282 | 11,865 | |
CBZ: carbamazepine; GBP: gabapentin; LEV: levetiracetam; LTG: lamotrigine; OXC: oxcarbazepine; PHB: phenobarbitone; PHT: phenytoin; TPM: topiramate; VPS: sodium valproate; ZNS: zonisamide
aOther treatment‐related reasons included: physician's decision, drug‐related death, pregnancy or perceived remission, or non specific (drug‐related) reason. bProportions for specific reasons indicate proportion of total events or total censored. Proportion for total events and total censored indicate the proportion of total participants. cOther non treatment‐related reasons included: epilepsy diagnosis changed, participants developed other medical disorders including neurological and psychiatric disorders or non specific (non drug‐related) reason. dWe treated those with missing reasons for withdrawal as censored in analysis and performed a sensitivity analysis treating these individuals as having withdrawal 'events.' Results of sensitivity analysis were practically identical and conclusions unchanged so we have presented the results treating these individuals as censored. eFour studies did not contribute to analysis of time to withdrawal of allocated treatment (Banu 2007; Craig 1994; Ogunrin 2005; Pal 1998).