Association between H. pylori infection and health Outcomes: an umbrella review of systematic reviews and meta-analyses

Objective Systematic reviews and meta-analyses have revealed the associations between H. pylori infection and various health outcomes. We aimed to evaluate the strength and breadth of evidence on the associations. Design Umbrella review of systematic reviews and meta-analyses. Setting No settings. Participants No patients involved. Data sources Embase, PubMed, Web of Science, Cochrane Library Databases, CNKI, VIP database and Wangfang database from inception to February 1, 2019. Outcomes measures Diverse diseases (such as cancer and ischaemic heart disease). Results Sixty articles reporting 88 unique outcomes met the eligible criteria. 74 unique outcomes had nominal significance (p<0.05). Of the outcomes with significance, 61 had harmful associations and 13 had beneficial associations. Furthermore, 73% (64) of the outcomes exhibited significant heterogeneity . Of the these meta-analyses, 32 had moderate to high heterogeneity (I-2=50%-75%) and 24 had high heterogeneity (I-2>75%). Moreover, 20% exhibited publication bias (p<0.1). In addition, 97% of the methodological qualities were rated 'critically low'. 36% of the evidence qualities of outcomes were rated 'low', 56% of the evidence qualities were rated 'very low' and 8% of the evidence qualities were rated 'moderate'. H. pylori infection may be associated with an increased risk of five diseases and a decreased risk of irritable bowel syndrome. Conclusion Although 60 meta-analyses explored 88 unique outcomes, moderate quality evidence only existed for six outcomes with statistical significance. H. pylori infection may be associated with a decreased risk of irritable bowel syndrome and an increased risk of hypertriglyceridemia, chronic cholecystitis and cholelithiasis, gestational diabetes mellitus, gastric cancer and systemic sclerosis.