Establishing gold standards for System-Level Measures: a modified Delphi consensus process. 
To establish aspirational 'gold standards' for a suite of System-Level Measures (SLMs) being used by Counties Manukau Health (CM Health), a New Zealand (NZ) District Health Board.  This study employed a multi-stage, multi-method modified Delphi consensus process.  The Delphi consensus process involved virtual (email) communication between participants (Round 1) and a structured face-to-face meeting (Round 2) held in Auckland, NZ.  Participants comprised of health professionals, managers, academics and quality improvement experts with an interest in the use of SLMs.  Participants in the first round received a letter requesting their participation in an anonymous Delphi.  The second round involved national and international health system experts taking part in a structured, facilitated face-to-face meeting.  Participants reviewed 15 SLMs in total.  The SLMs all related to the three domains of the Triple Aim: Population Health, e.g. life expectancy at birth; Patient Experience of Care, e.g. rate of adverse events; and Cost and Productivity, e.g. healthcare expenditure per capita.  For a proposed gold standard to be agreed and established for each SLM.  Twelve participants took part in Round 1, with 19 participating in Round 2.  The process established agreement on a gold standard for each of the 15 reviewed SLMs.  We demonstrated that the Delphi consensus process can be used to establish gold standards for a suite of SLMs used by a NZ Health Board (CM Health).