Summary of findings for the main comparison. Any anticonvulsant versus placebo for cocaine dependence.
| Any anticonvulsant versus placebo for cocaine dependence | ||||||
| Patient or population: patients with cocaine dependence Settings: outpatients Intervention: any anticonvulsant versus placebo | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Control | Any anticonvulsant versus placebo | |||||
| Dropout Number of participants who did not complete the treatment Follow‐up: mean 11.8 weeks1 | 45 per 100 | 42 per 100 (38 to 47) | RR 0.95 (0.86 to 1.05) | 1695 (17 studies2) | ⊕⊕⊕⊝ Moderate3,4 | |
| Use of cocaine (self reported or objective) Number of participants who reported the use of cocaine during treatment, and/or number of participants with urine samples positive for cocaine Follow‐up: mean 11.8 weeks1 | 77 per 100 | 71 per 100 (65 to 79) | RR 0.92 (0.84 to 1.02) | 867 (9 studies5) | ⊕⊕⊕⊝ Moderate6,7 | |
| Side effect Number of participants reporting at least 1 side effect and types of side effects experienced during treatment Follow‐up: mean 11.8 weeks1 | 46 per 100 | 65 per 100 (47 to 88) | RR 1.39 (1.01 to 1.9) | 775 (8 studies) | ⊕⊕⊝⊝ Low8,9 | |
| Craving (BSCS) Measured by validated scales (e.g. Brief Substance Craving Scale (BSCS)) Follow‐up: mean 11.8 weeks1 | The mean craving (bscs) in the intervention groups was 0.25 standard deviations lower (0.59 lower to 0.09 higher) | 428 (7 studies11) | ⊕⊕⊝⊝ Low11,12,13 | |||
| *The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio. | ||||||
| GRADE (Grades of Recommendation, Assessment, Development and Evaluation) Working Group grades of evidence. High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. | ||||||
1 Range 8 ‐ 24 weeks 2 20 treatment arms 3 In the Cornish 1995, Halikas 1997 arm a, Halikas 1997 arm b;Nuijten 2014, Umbricht 2014 studies an adequate sequence generation method was described and judged at low risk of selection bias. In the other 17 studies the method was not reported (unclear risk of bias). In five studies (Brodie 2009, Cornish 1995, Gonzalez 2007 arm a, Gonzalez 2007 arm b, Kranzler 1995, Umbricht 2014) an adequate method for allocation concealment was judged at low risk of selection bias. In all the other studies the method for allocation concealment was not reported (unclear risk of bias). Campbell 1994 arm was judged at high risk of selective reporting bias because results for drop out were not reported. 4 All the seventeen included studies were conducted in the USA 5 11 treatment arm 6 In the Cornish 1995, Halikas 1997 arm a, Halikas 1997 arm b;Nuijten 2014 studies an adequate sequence generation method was described and judged at low risk of selection bias. In the other studies the method was not reported (unclear risk of bias). In three studies (Brodie 2009, Cornish 1995, Gonzalez 2007 arm a, Gonzalez 2007 arm b) an adequate method for allocation concealment was judged at low risk of selection bias. In all the other studies the method for allocation concealment was not reported (unclear risk of bias). Nuijten 2014 were judged at high risk of performance bias and at unclear risk of detection bias All the other studies were judged at low risk of performance and detection bias. Cornish 1995, Halikas 1997 arm a, Halikas 1997 arm b, Kranzler 1995, Nuijten 2014 were judged at high risk of attrition bias. 7 I‐squared 30% 8 In the Brown 2012, Cornish 1995 and Nuijten 2014 studies an adequate sequence generation method was described and judged at low risk of selection bias. In the other studies the method was not reported (unclear risk of bias).One study was judged at high of bias ( Brown 2012) for allocation concealment. All the studies were judged at low risk of performance and detection bias. Brown 2012, Cornish 1995, Crosby 1996, Kranzler 1995, Nuijten 2014) were judged at high risk of attrition bias. All the other studies performed the analysis on the intention to treat basis or did not have withdrawn from the study. 9 I‐squared 81% 10 Eight treatment arms 11In the Nuijten 2014 studies an adequate sequence generation method was described and judged at low risk of selection bias. In the other studies the method was not reported (unclear risk of bias). In all the studies the method for allocation concealment was not reported (unclear risk of bias). Berger 2005 arm a, Berger 2005 arm b and Nuijten 2014 were judged at high risk of performance bias and at unclear risk of detection bias. Winhusen 2005 was judged at high risk both for performance and detection bias. Crosby 1996 and Nuijten 2014 were judged at high risk of attrition bias. 12I‐squared 63% 13 All the seven included studies were conducted in the USA