Footnotes

• Twitter Follow Erica Spatz at @SpatzErica and Andi Shahu at @andishahu

• Contributors AS and ESS had full access to the data and take responsibility for the accuracy of the data analysis and interpretation of findings.

• Funding ESS is supported by grant K12HS023000 from the Agency for Healthcare Research and Quality Patient Centered Outcomes Research Institutional Mentored Career Development Program. HMK is supported by grant U01 HL105270-05 (Center for Cardiovascular Outcomes Research at Yale University) from the National Heart, Lung, and Blood Institute.

• Competing interests ESS, JS, SMB, HMK and MP report receiving support from the Centers for Medicare and Medicaid Services to develop and maintain performance measures that are used in public reporting programmes; they are currently developing a measure of informed consent document quality. HMK is a recipient of research agreements from Medtronic and from Johnson & Johnson (Janssen), through Yale University, to develop methods of clinical trial data sharing and chairs a cardiac scientific advisory board for UnitedHealth.

• Provenance and peer review Not commissioned; externally peer reviewed.