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In this new phase, the aim is to conduct individual patient-level data (IPD) meta-analyses involving eligible BP-lowering randomised controlled trials (RCTs) to address uncertainties relating to efficacy and safety of BP-lowering treatment.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods and analysis<\/jats:title><jats:p>RCTs investigating the effect of pharmacological BP-lowering, with a minimum of 1000 patient-years of follow-up in each trial arm, are eligible. Our systematic review identified 100 potentially eligible trials. We requested their investigators\/sponsors to contribute baseline, follow-up and outcomes data. As of June 2018, the collaboration has obtained data from 49 trials (n=315\u2009046 participants), with additional data currently in the process of being transferred from four RCTs (n=34\u2009642 participants). In addition, data harmonisation has commenced. Scientific activities of the collaboration are overseen by the Steering Committee with input from all collaborators. Detailed protocols for individual meta-analyses will be developed and registered on public platforms.<\/jats:p><\/jats:sec><jats:sec><jats:title>Ethics and dissemination<\/jats:title><jats:p>Ethics approval has been obtained for this new and extended phase of the BPLTTC, the largest collaboration of de-identified IPD from RCTs. It offers an efficient and ethical manner of re-purposing existing data to answer clinically important questions relating to BP treatment as well as methodological questions relating to IPD meta-analyses. Among the immediate impacts will include reliable quantification of effects of treatment modifiers, such as baseline BP, age and prior disease, on both vascular and non-vascular outcomes. Analyses will further assess the impact of BP-lowering on important, but less well understood, outcomes, such as new-onset diabetes and renal disease. Findings will be published in peer-reviewed medical journals on behalf of the collaboration.<\/jats:p><\/jats:sec>","DOI":"10.1136\/bmjopen-2018-028698","type":"journal-article","created":{"date-parts":[[2019,5,23]],"date-time":"2019-05-23T12:45:33Z","timestamp":1558615533000},"page":"e028698","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":35,"title":["Investigating the stratified efficacy and safety of pharmacological blood pressure-lowering: an overall protocol for individual patient-level data meta-analyses of over 300 000 randomised participants in the new phase of the Blood Pressure Lowering Treatment Trialists\u2019 Collaboration (BPLTTC)"],"prefix":"10.1136","volume":"9","author":[{"given":"Kazem","family":"Rahimi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dexter","family":"Canoy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Milad","family":"Nazarzadeh","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gholamreza","family":"Salimi-Khorshidi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark","family":"Woodward","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Koon","family":"Teo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barry R","family":"Davis","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John","family":"Chalmers","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carl J","family":"Pepine","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2019,5,22]]},"reference":[{"key":"2020050713491346000_9.5.e028698.1"},{"key":"2020050713491346000_9.5.e028698.2","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCULATIONAHA.115.018912"},{"key":"2020050713491346000_9.5.e028698.3","doi-asserted-by":"publisher","DOI":"10.1161\/CIRCRESAHA.116.304723"},{"key":"2020050713491346000_9.5.e028698.4","first-page":"162","article-title":"Usual blood pressure, atrial fibrillation and vascular risk: evidence from 4.3 million adults","volume":"46","author":"Emdin","year":"2017","journal-title":"Int J Epidemiol"},{"key":"2020050713491346000_9.5.e028698.5","doi-asserted-by":"publisher","DOI":"10.1161\/STROKEAHA.116.012658"},{"key":"2020050713491346000_9.5.e028698.6","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.h4865"},{"key":"2020050713491346000_9.5.e028698.7","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2015.07.059"},{"key":"2020050713491346000_9.5.e028698.8","first-page":"127","article-title":"Protocol for prospective collaborative overviews of major randomized trials of blood-pressure-lowering treatments. 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