Systematic reviews of pharmacological and nonpharmacological treatments for patients with chronic urticaria: An umbrella systematic review

A wide range of pharmacological and nonpharmacological interventions for chronic urticaria (CU) have been evaluated in systematic reviews (SRs). We conducted an umbrella review of SRs of the effectiveness and safety of pharmacological and nonpharmacological interventions for CU, which allow the findings of separate reviews to be compared and contrasted and thereby provide decision makers in healthcare with the evidence they need. We included SRs evaluating pharmacological and nonpharmacological interventions for CU. Comprehensive searches were conducted in 7 bibliographic databases, relevant journals up to July 2018. Two reviewers independently assessed the studies’ relevance and quality. The assessment of multiple systematic reviews tool and grading of recommendations assessment, development and evaluation method was used to assess the methodological quality of the SRs and classify the quality of the outcomes. In total, 41 SRs were included. Thirty-seven reviews performed quantitative research syntheses, and 4 reviews performed qualitative research syntheses. The majority of SRs evaluated interventions based on combination therapies, antihistamines, traditional Chinese medicines, autohemotherapy, omalizumab, acupuncture, cyclosporine, and leukotriene receptor antagonist. Positive intervention outcomes were reported in the majority (75.32%) of the reviews. However, the methodological quality and evidence quality of the reviews were generally poor. There is some evidence to support a variety of interventions for CU. However, there was much heterogeneity in evidence quality among SRs. Many of the SRs had methodological weaknesses that make them vulnerable to bias. Moreover, there remained little information on the relative effectiveness of one intervention compared with another. Therefore, further SRs that adherence to strict scientific methods are necessary, and primary studies make comparisons between the different treatment options directly.