Study designs of evaluations included in the review
Randomised controlled trials (RCTs) were eligible for inclusion in the review. One included study was a within-subject design, while the remainder were between-subjects designs.
Specific interventions included in the review
There was confusion over the inclusion criteria relating to the interventions. In the text of the review, the authors stated that studies that compared topical 20% azelaic acid cream or 15% azelaic acid gel at any dose with vehicle control formulations were eligible for inclusion in the review. However, the objective and inclusion criteria in the abstract clearly stated that studies that compared azelaic acid formulations with other topical treatments and metronidazole were eligible. The authors specifically excluded two studies that compared azelaic acid formulations with 0.75% metronidazole, but these featured prominently in the review discussion. All studies included in the review compared azelaic acid cream or gel with the respective vehicles over periods of 9 weeks to 3 months. All included studies disallowed concomitant therapy with the potential to affect the course of rosacea.
Participants included in the review
Studies of patients of any age and either gender, with a diagnosis of papulopustular rosacea, were eligible for inclusion. The majority of patients in most included studies were female.
Outcomes assessed in the review
The primary outcome included in the review was physician-assessed changes in the severity of rosacea, as determined by counts of inflammatory lesions. The secondary outcomes were measures of physician or device-assessed changes in rosacea severity, including severity of erythema and telangiectasia. The included studies also reported treatment-related adverse events. Studies used different rating systems to grade erythema severity.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed the studies for inclusion in the review and resolved any disagreements through discussion.