Summary of findings 5. Etretinate compared to placebo or no treatment for chronic palmoplantar pustulosis.
| Etretinate compared to placebo or no treatment for chronic palmoplantar pustulosis | ||||||
| Patient or population: chronic palmoplantar pustulosis Setting: not reported Intervention: etretinate Comparison: placebo or no treatment | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | No. of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with placebo or no treatment | Risk with etretinate | |||||
| Proportion of participants cleared or almost cleared in the short term (10 weeks or 4 months) | Study population | RR 3.48 (0.82 to 14.80) | 40 (2 RCTs) | ⊕⊝⊝⊝ Very lowa | Another study assessing this comparison ‐ White 1986 (20 participants) ‐ reported zero participants cleared in both groups. | |
| 100 per 1000 | 348 per 1000 (82 to 1000) | |||||
| Proportion of participants with adverse effects serious or severe enough to have caused withdrawal ‐ not reported | ‐ | ‐ | ‐ | ‐ | ‐ | Not reported |
| Proportion of participants with at least 50% improvement in their quality of life ‐ not reported | ‐ | ‐ | ‐ | ‐ | ‐ | Not reported |
| Proportion of participants achieving a 50% reduction in disease severity ‐ not reported | ‐ | ‐ | ‐ | ‐ | ‐ | Not reported |
| Proportion of participants without relapse in the long term (6 months) | Study population | RR 2.39 (0.92 to 6.17) | 26 (1 RCT) | ⊕⊝⊝⊝ Very lowb | ‐ | |
| 267 per 1000 | 637 per 1000 (245 to 1000) | |||||
| Proportion of participants with adverse effects ‐ measured over 12 weeks | Study population | RR 3.50 (0.95 to 12.90) | 20 (1 RCT) | ⊕⊝⊝⊝ Very lowa | Four participants had cheilitis, 2 had facial dermatitis, and 1 developed some hair loss in the etretinate group compared with 2 participants with cheilitis in the placebo group (White 1986). | |
| 200 per 1000 | 700 per 1000 (190 to 1000) | |||||
| Ease of compliance to an intervention or a treatment ‐ not reported | ‐ | ‐ | ‐ | ‐ | ‐ | Not reported |
| *The risk in the intervention group (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; RCT: randomised controlled trial; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence. High quality: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low quality: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aDowngraded by three levels to very low‐quality evidence: two levels due to study limitations as the two trials are at risk of bias for blinding because of systematic visible adverse events due to etretinate, and one further level for imprecision because both trials included a small number of participants.
bDowngraded by three levels to very low‐quality evidence: two levels because of study limitations (high risk of bias for blinding and incomplete outcome data) and one level due to imprecision because only one trial including a small number of participants assessed this comparison.