In defence of our research on competition in England's National Health Service/Authors' reply

Pollock and colleagues also lambast the use of acute myocardial infarction (AMI) as a quality measure, arguing that "the fact that they might be correlated with waiting times or length of stay for elective knee replacement or hip replacement does not make them a valid proxy measure of safety or quality of elective care". Furthermore, Gaynor and colleagues4 examined a battery of measures constructed by the National Clinical and Health Outcomes Knowledge Base, and found that greater competition was linked to improvements in length of stay, overall hospital mortality rates, and overall mortality rates excluding AMI care. Published Online November 8, 2011 DOI:10.1016/S0140- 6736(11)61708-X See Comment page 2057 For the extended point-bypoint response see http://cep. lse.ac.uk/textonly/_new/ research/productivity/lancet_ LONGrep.pdf Submissions should be made via our electronic submission system at http://ees.elsevier.com/ thelancet/ Nicholas Bloom, *Zack Cooper, Martin Gaynor, Stephen Gibbons, Simon Jones, Alistair McGuire, Rodrigo Moreno-Serra, Carol Propper, John Van Reenen, Stephan Seiler z.cooper@lse.ac.uk Stanford University, Stanford, CA, USA (NB, SS); London School of Economics, London, WC2A 2AE, UK (ZC, SG, AM, JVR); Carnegie Mellon University, Pittsburgh, PA, USA (MG); University of Surrey, Guildford, UK (SJ); Imperial College London, London, UK (RM-S, CP); and Centre for Economic Performance, Swindon, UK (JVR) 1 Pollock A, Macfarlane A, Kirkwood G, et al.