The Wennberg International Collaborative (WIC) was founded in 2010 by Dr. David Goodman of The Dartmouth Institute for Health Policy & Clinical Practice (U.S.) and Professor R. Gwyn Bevan of the London School of Economics and Political Science (U.K.). The inaugural meeting was held at the London School of Economics and Political Science in 2010.

The goal of the Collaborative is to accelerate research into the causes and consequences of unwarranted health care variation across regions and providers. The WIC was initiated in  response to the complex and often controversial nature of this research.

The Collaborative seeks to reduce barriers in the field through sponsoring research and policy meetings, facilitating collaboration amongst members, advocating for healthcare data availability, and serving as a clearinghouse for research and policy findings. The primary focus of the WIC is variation in health system performance within countries, although some members also examine variation across countries. The WIC is a community of scholars and policymakers (and their interests, ideas, and technical capabilities) that provides support to emerging investigators and projects. Presentation topics during meetings range from new critical questions, novel methods, recent findings, and innovative policy and improvement ideas.

Centre for Clinical Documentation and Evaluation (SKDE) was established in 2004.

SKDE contributes to highlighting geographical inequalities in the specialist healthcare service in Norway with the aim to contribute to equal healthcare services of good quality. Among SKDE’s primary tasks is to produce Health Atlases that provide an overview of the use of specialist healthcare in Norway.

SKDE has several ongoing research projects studying the geographical and socio-economical variation in healthcare services within various fields: cardiovascular diseases, cancer, mental health, and musculoskeletal disorders.

SKDE has also been tasked with leading an interregional effort to reduce examinations and treatments with low value or uncertain health benefits in specialist healthcare. 

The National centre for Medical Quality Registers is organized in SKDE and offers support with the establishment and operation of national clinical quality registers.

The centre has a total of 38 employees, led by Director Eva Stensland, and is located in Tromsø, Norway.

IQ Health is one of the three scientific departments at the Radboud University Medical Center in Nijmegen, the Netherlands. A state-of-the-art department with the core tasks of research and education.

One of our research topics is practice variation / regional variation in health care utilization, quality and costs.

IQ health has been part of the WIC community since the early 2000’s, and we are also proud to contribute to the Journal of Research in Health Services and Regions (RHSR), which is closely connected to the WIC.

Theme leader - Eva Stensland

Low-value care has no added value for the patient and may be harmful. To increase quality of care, healthcare systems aim to reduce low-value care, through de-implementation strategies.  De-implementations also supports healthcare systems sustainability reducing wasteful spending and carbon emissions. De-implementation is a challenge because of the many causes of low-value care with responsibility at different levels: patients, professional, organization, and system. In some de-implementation initiatives, healthcare may be replaced by high value care, but other times there is no substitute. Behavioral change is often essential for both healthcare providers and patients. De-implementation requires a tailored strategy based on an inventory of barriers and facilitators. Contributions on this topic include:

• How can we identify low-value care? What role can practice variation analysis play?
• Why do we still provide low-value care?
• What strategies are effective to reduce low-value care? And which are sustainable?
• What are the financial consequences of reducing low-value care?
• How can we spread and sustain effective strategies?

Theme leader -  Stef Groenewoud  

To call variation in care ‘unwarranted’ implies a normative view of what constitutes “good care”. That raises moral questions that we would like to explore in this year’s WIC.

We invite contributions discussing:

• Existing frameworks for understanding / discerning warranted and unwarranted variation:
  • do/should frameworks take into account ethics?
  • do they also apply to controversial decisions (e.g., at the end of life)?
• Ethics of public reporting (hospital or doctor level)
  • Who owns the data?
  • Right to / access to information
• Age based rationing in health care
  • to prevent overuse/misuse
  • on grounds of cost-effectiveness (giving priority to the young)
• Moral questions regarding incentives for
  • reducing unwarranted variation
  • quality improvement

Theme leader - To be decided 

The lack of patient agency has been identified as one cause for unwarranted variation, when a diagnostic or therapeutic decision has options each with a differing profile of benefits and adverse effects. Decision aids and shared decision-making can increase decision quality (i.e., improved patient knowledge, value clarification, and meaningful engagement in the decision-making process), patient satisfaction, and outcomes.  We invite contributions that focus on understanding and improving patient engagement in important clinical decisions.

Theme leader - To be decided

Moving from evaluating to understanding and changing health care, is greatly informed through qualitative research designs and methods. Qualitative methods can help interpret, understand and make sense of (“verstehen”) differences found. We are particularly interested in researchers in applying qualitative and mixed methods to better understanding practice variation and the next step: quality improvement.

We invite contributions that include:

• interview studies;
• group discussions and focus groups;
• observational studies;
• grounded theory approaches;
• ethnographic studies
• case studies.

Theme leader - Zeynep Or and Jostein Grytten

The gold standard for cause-effect studies is randomized controlled experiments. For several reasons (ethical, financial and political), such experiments are difficult to carry out in studies of practice variation and can lack generalizability to the general population. Hence many studies rely on observational data (i.e., data in which exposure is determined in a different way than random assignment) but it difficult to establish causal inference with the most commonly used study designs.  Causal inference is required to answer questions such as: What is the impact of hospital payment on practice variation? What is the effect of a specific intervention (such as care protocols) in reducing variation in medical practice? To what extent does an increase in the number of beds increase variation? Econometricians have led the development of methods to examine causality using observational data. Examples are difference-in-difference, regression discontinuity or instrumental variables methods. These methods can be challenging to use.

The aim of the session is to discuss the potential benefits and limitations of these methods, their application in specific research.  We welcome all types of work, both in progress and nearly completed. If you have a draft of your work, we may be able to get somebody to give prepared comments. 

Theme leader - Therese Stukel

Population-based health care measurement across regions and providers commonly begins with the analysis of health administrative data that has been collected for billing purposes, but the scope and scale of these data differs across regions even within the same country. Some countries have access to rich population-based data that is linkable across health care sectors and time as well as across different domains such as health, education and justice. In many places, researchers and policy analysts have access to other rich data sources that can be linked to patients such as clinical registries, patient and provider surveys, and electronic medical data (EMR). In this session, we will explore the use of novel data sources and data linkage methods to enhance our understanding of the causes and consequences of unwarranted variation.

Effective care has been defined as health interventions where evidence and professional consensus indicate that benefits far outweigh any attendant risks.  Unwarranted variation in effective care indicates health care underuse that is likely to cause harm to patients and populations.  The WIC welcomes papers related to causes and remedies of effective care.

In 2021, the U.S. National Library of Medicine recognized the important of the concept of “overdiagnosis” by adding the term to its list of Medical Subject Headings. “The labeling of a person with a disease or abnormal condition that would not have caused the person harm if left undiscovered, creating new diagnoses by medicalizing ordinary life experiences, or expanding existing diagnoses by lowering thresholds or widening criteria without evidence of improved outcomes. Individuals derive no clinical benefit from overdiagnosis, although they may experience physical, psychological, or financial harm.” The WIC welcomes papers that describe and investigate the problem of regional and provider variation in overdiagnosis.

Gwyn Bevan

There is so much truth in Paul Batalden’s haunting observation ‘Every system is perfectly designed to get the results it gets’.  Hence the paradox: despite fundamental differences between countries in their systems of organizing the finance and delivery of health care, one troubling outcome that these different systems have in common is that they are perfectly designed to produce unwarranted variations. This theme has two objectives.

• First, to identify the causes of those outcomes from systemic characteristics of incentives (of providers of care) and the default options in the available choice architecture.

For example, in England the default option for a general practitioner who wearies of having to see the same patient every week with low back pain is to make a referral for an MRI scan. This is costly and of no benefit to the patient, but means the general practitioner won't have to see the patient for weeks, and patient is happier because something is being done.

• Second, working out the obstacles to systemic change, and where it is possible to overcome these by changing the incentives and choice architectures to reduce unwarranted variations.

For example, for low back pain develop online help and local exercise classes.