{"doi":"10.1111/bcp.14310","title":"Effect of low‐dose aspirin on health outcomes: An umbrella review of systematic reviews and meta‐analyses","abstract":"<h4>Aims</h4>This study aimed to use an umbrella review methodology to capture the range of outcomes that were associated with low-dose aspirin and to systematically assess the credibility of this evidence.<h4>Methods</h4>Aspirin is associated with several health outcomes, but the overall benefit/risk balance related to aspirin use is unclear. We searched three major databases up to 15 August 2019 for meta-analyses of observational studies and randomized controlled trials (RCTs) including low-dose aspirin compared to placebo or other treatments. Based on random-effects summary effect sizes, 95% prediction intervals, heterogeneity, small-study effects and excess significance, significant meta-analyses of observational studies were classified from convincing (class I) to weak (class IV). For meta-analyses of RCTs, outcomes with random effects P-value < .005 and a moderate/high GRADE assessment, were classified as strong evidence. From 6802 hits, 67 meta-analyses (156 outcomes) were eligible.<h4>Results</h4>Observational data showed highly suggestive evidence for aspirin use and increased risk of upper gastrointestinal bleeding (RR = 2.28, 95% CI: 1.97-2.64). In RCTs of low-dose aspirin, we observed strong evidence for lower risk of CVD in people without CVD (RR = 0.83; 95% CI: 0.79-0.87) and in general population (RR = 0.83; 95% CI: 0.79-0.89), higher risk of major gastrointestinal (RR = 1.47; 95% CI: 1.26-1.72) and intracranial bleeding (RR = 1.34; 95% CI: 1.18-1.53), and of major bleedings in people without CVD (RR = 1.62; 95% CI: 1.26-2.08).<h4>Conclusion</h4>Compared to other active medications, low-dose aspirin had strong evidence for lower risk of bleeding, but also lower comparative efficacy. Low-dose aspirin significantly lowers CVD risk and increases risk of bleeding. Evidence for multiple other health outcomes is limited.","journal":"British Journal of Clinical Pharmacology","year":2020,"id":10501,"datarank":0.44166584687496613,"base_score":2.9444389791664403,"endowment":2.9444389791664403,"self_citation_contribution":0.44166584687496613,"citation_network_contribution":0.0,"self_endowment_contribution":0.44166584687496613,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":18,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.0857,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-06-02","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":688,"name":"Jacopo Demurtas","orcid":"0000-0003-3001-8546","position":1,"is_corresponding":false},{"id":24216,"name":"Trevor Thompson","orcid":"0000-0001-9880-782X","position":2,"is_corresponding":false},{"id":679,"name":"Marco Solmi","orcid":"0000-0003-4877-7233","position":3,"is_corresponding":false},{"id":683,"name":"Gabriella Pesolillo","orcid":"0000-0003-3282-3901","position":4,"is_corresponding":false},{"id":674,"name":"Stefano Celotto","orcid":"0000-0003-3203-1664","position":5,"is_corresponding":false},{"id":678,"name":"Tommaso Barnini","orcid":null,"position":6,"is_corresponding":false},{"id":680,"name":"Brendon Stubbs","orcid":"0000-0001-7387-3791","position":7,"is_corresponding":false},{"id":38891,"name":"Stefania Maggi","orcid":"0000-0002-1043-7674","position":8,"is_corresponding":false},{"id":87176,"name":"Alberto Pilotto","orcid":null,"position":9,"is_corresponding":false},{"id":87177,"name":"Graziano Onder","orcid":"0000-0003-3400-4491","position":10,"is_corresponding":false},{"id":87178,"name":"Alberto Vaona","orcid":null,"position":12,"is_corresponding":false},{"id":24222,"name":"Joseph Firth","orcid":"0000-0002-0618-2752","position":13,"is_corresponding":false},{"id":681,"name":"Lee Smith","orcid":"0000-0002-5340-9833","position":14,"is_corresponding":false},{"id":22610,"name":"Parvaiz A Koul","orcid":"0000-0002-1700-9285","position":15,"is_corresponding":false},{"id":685,"name":"Ioanna Tzoulaki","orcid":"0000-0002-4275-9328","position":17,"is_corresponding":false},{"id":691,"name":"Evropi Τheodoratou","orcid":"0000-0001-5887-9132","position":18,"is_corresponding":false},{"id":148,"name":"John P. A. Ioannidis","orcid":"0000-0003-3118-6859","position":19,"is_corresponding":false},{"id":687,"name":"Nicola Veronese","orcid":"0000-0002-9328-289X","position":0,"is_corresponding":true}],"reference_count":53,"raw_metadata":null,"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}