Data Statement

Driving Health Care Improvement Without a Map: A Call for Improved Data Availability
London, UK September 4, 2015

Unwarranted variation in health care utilization, quality, outcomes, costs and efficiency among regions and health care systems is a pervasive and persistent problem, (OECD, 2014) and, by definition, represents differences in the performance of health care systems, rather than in population needs or preferences. But most countries lack a system of health care surveillance that could identify what problems occur and where, and that could monitor progress towards health care improvement. As seen in a recent survey of attendees of the Wennberg International Collaborative (, a research network to promote the study of unwarranted variation, the availability of health care data to independent researchers and policy analysts in most countries is limited. While some countries are doing a good job at organizing and releasing health care data to researchers, in many other countries such data is incomplete, difficult to access, and costly. Researchers report that governments, insurers, and health care providers often effectively block public release of data required to monitor health system performance. These barriers to data access hide important differences in quality from the public view, slow the development of research into the causes of health care unwarranted variation, and prevent the evaluation of programs intended to improve health care.

Information on the patterns of health care performance is an essential component of well functioning and efficient national health care systems. Health care data helps to identify and locate:

  1. Regions, areas, and health care systems that lag or lead in delivering high quality and efficient care,
  2. Problems in the provision of care,
  3. The causes of unwarranted variation, and
  4. the magnitude of public benefit, if problems in care were remedied.

Measuring avoidable variation helps identify misused resources that can be reallocated to achieve better value at a time when health systems are struggling to be sustainable without sacrificing equity. Better public transparency and research on variation in health care performance accelerates improvements in care with benefits to patients while reducing costs. The absence of data blinds patients, physicians, health care managers, and policymakers from the information needed to understand and improve care. Data gathering, data access and independent data analysis are essential to the national provision of high value health care.

A Call for Action:

We, as members of the Wennberg International Collaborative, call for full and open access to health care data and information for legitimate research and policy analysis.

Principles in Access to Health Care Data:

  • Data about patients and populations are owned by patients and the public, and therefore ought be accessible for independent analysis for improving population health and health care, subject to protection of patient confidentiality.
  • Protecting patient confidentiality ought to be guaranteed using proven techniques so that this protection ought not become a pretext for hindering access to data for legitimate independent researchers and policy analysts. Patient privacy rights are aligned with the public right to have data that improves care.
  • Information about variation in health system performance ought to be available to the public to benefit patient populations.

Steps that should be taken to promote access to health care data in the public interest:

  • Develop national data trusts that organize health care, health, and population data from different data holders (e.g. providers, insurers, national and regional health systems).
  • Continue to develop and implement standards of completeness and quality of health care data.
  • Promote greater transparency in health care system performance by allowing the identification and comparisons of regions and health care systems, while maintaining patient confidentiality.
  • Establish systems of efficient administrative and ethical review to respond to data requests from researchers and policy analysts in a timely fashion.

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Signed by:

John “Jack”  Wennberg
The Dartmouth Institue for Health Policy & Clinical Practice, USA

Gert Westert
IQ Healthcare, Nijmegen, The Netherlands

David Goodman
The Dartmouth Institue for Health Policy & Clinical Practice, USA

Gwyn  Bevan
London School of Economics and Political Science, UK

Enrique Bernal-Delgado 
Institute for Health Sciences in Aragón, Spain

Michael Barry 

Claudia Berlin
University of Bern, Switzerland

Jan Bocken
The Bertelsmann Foundation, Germany

Paulo Boto
Escola Nacional de Saúde Pública (ENSP)/Universidade Nova de Lisboa (UNL), Protugal

Anne Brabers
NIVEL, Netherlands

Cecilia Cazaban 

Sandra Garcia-Armesto
Institute for Health Sciences in Aragón, Spain

Marion Grote-Westrick
Bertelsmann Stiftung, Germany

Jostein Grytten

Astrid Guttmann
Institute for Clinical Evaluative Sciences, Canada

Dougal Hargreaves 
UCL Institute of Child Health, UK

Illir Hoxha 

Erica Ison 

Søren Johnsen

Judith de Jong 
The Netherlands

Ilmo Keskimaki
National Institute for Health and Welfare, Finland

Troels Kristensen 

Pia Kristensen
Department of Clinical Epidemiology, Denmark

Anne Kudsk Fallesen 

Heeyoung Lee 
South Korea

Linda Leivseth
Centre for Clinical Documentation and Evaluation (SKDE), Norway

Xhyljeta Luta
University of Bern, Institute of Social and Preventive Medicine (ISPM), Switzerland

Ceu Mateus
Lancaster University, UK

Ducan McPherson 

Gregoire Mercier
CHU Montpellier, France

Mats Nilsson
Futurum – Academy for Health and Care Region Jönköping County, Sweden

Frede Olesen
Res. Unit for GP, Aarhus University, Denmark

Tetsuya Otbsubo
Kyoto University, Japan

Adrian Pana 

Vittoria Polito
Public Health England, UK

Milo Puhan
University of Zurich, Switzerland

Shwan Ralston
Children’s Hospital at Dartmouth, USA

Ingvild Mathiesen Rosenlund
UiT The Arctic University of Tromsø, Norway

Jessica Sheringham

Matthew Skellern
London School of Economics, UK

Afrin Steindal
SKDE, Norway

Leonie Sundmacher
Ludwig Maximilians University Munich, Germany

Andreas Taenzer
Dartmouth College, USA

Diane Watson
National Health Performance Authority, Australia

William Weeks
The Dartmouth Institue for Health Policy & Clinical Practice, USA