Summary of findings 1. Azelaic acid compared to adapalene.
| Azelaic acid compared to adapalene for acne | ||||||
| Patient or population: participants with acne Settings: industry‐sponsored, single‐site study in Germany (1 study) Intervention: topical azelaic acid Comparison: topical adapalene | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No. of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Topical adapalene | Topical azelaic acid | |||||
|
Participants' global self‐assessment of acne improvement Improved to very much improved (long term: treatment duration > 8 weeks) |
842 per 1000 | 749 per 1000 (573 to 985) | RR 0.89 (0.68 to 1.17) | 55 (1 study) | ⊕⊝⊝⊝ Very lowa | ‐ |
|
Withdrawal for any reason (long term: treatment duration > 8 weeks) |
53 per 1000 | 139 per 1000 (17 to 1000) | RR 2.64 (0.33 to 20.99) | 55 (1 study) | ⊕⊝⊝⊝ Very lowb | ‐ |
|
Total number of participants who experienced at least one minor adverse event (medium term: treatment duration from 5 to 8 weeks) |
263 per 1000 | 305 per 1000 (124 to 750) | RR 1.16 (0.47 to 2.85) | 55 (1 study) | ⊕⊝⊝⊝ Very lowc | The authors reported no "significant difference" in the incidence of erythema, dryness, and itching between treatment groups. |
|
Quality of life Dermatology Life Quality Index (long term: treatment duration > 8 weeks) |
The authors reported that there was no "statistically significant" difference (P = 0.549) between azelaic acid and adapalene. | 55 (1 study) |
⊕⊝⊝⊝ Very lowd |
Skewed data reported. | ||
| *The basis for the assumed risk (e.g. the 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 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. | ||||||
aDowngraded by three levels to very low quality evidence. One level for risk of bias: only one study included, and study had unclear allocation concealment and high risk of performance bias. Two levels for imprecision: wide CI and optimal sample size not met. bDowngraded by three levels to very low quality evidence. One level for risk of bias: only one study included, with unclear allocation concealment and high risk of performance bias. Two levels for imprecision: very wide CI and optimal sample size not met. cDowngraded by three levels to very low quality evidence. One level for risk of bias: only one study included, with high risk of performance bias and unclear allocation concealment and blinding of outcome assessment. Two levels for imprecision: wide CI and optimal sample size not met. dDowngraded by three levels to very low quality evidence. One level for risk of bias: only one study included with unclear allocation concealment and high risk of performance bias. Two levels for imprecision: very small population size. *We choose a mean baseline risk from the studies included in meta‐analysis, calculated as number of participants in the control groups with event divided by total number of participants in control groups (study population) as assumed risk.